That’s by no means a certainty; the sign-up website is doing better, some insurance carriers are extending plans instead of canceling them, and there are millions more uninsured people who stand to get covered than there are covered people facing plan cancellations. Medicaid sign-ups are also running strong.

Still, the estimated 4 million to 5 million — there are no official numbers, just industry guesstimates — getting plan cancellation notices have had a giant media megaphone, a Republican chorus and a story to tell about how President Barack Obama broke a promise that if they liked their health plans, they could keep them. And some of them need to get new coverage before the first of year.

( Understanding Obamacare: POLITICO’s guide to the ACA)

That’s put a lot of pressure on closing that potential coverage gap by Dec. 23, the last day people can sign up for Obamacare coverage that starts Jan. 1. Here are some of the options for people facing plan cancellations.

Shop on the exchanges

This was the Obama administration’s preferred solution all along, but it was extraordinarily difficult for the past two months in the 36 states that depend on HealthCare.gov and in a handful of state exchanges like Oregon that have tech problems of their own.

That amplified the political backlash from the wave of cancellation letters. People losing their plans couldn’t check out their options — or find out if they could get a subsidy, in some cases worth thousands of dollars.

“It was unbelievably frustrating,” said Michael McGrath, a self-employed Illinois man who said the policy for his wife and three children was canceled. “The website didn’t work at all — it was the perfect evidence for people who say the public sector can’t do anything like this. And we really did not know what we could do.” In a conversation early this week, the family was still trying to figure it out.

( PHOTOS: 12 Democrats criticizing the Obamacare rollout)

Republicans are curating stories of people gobsmacked by cancellations, which often come with offers of an alternative, Obamacare-compliant policy that is considerably more expensive because it includes richer benefits and is available to the sick as well as the well.

Independent Women’s Voices, a group that opposes Obamacare, launched a website — mycancellation.com, that has gathered hundreds of pictures of cancellation letters. “You can’t deny the real-life experience of people who receive a letter in the mail that says you can’t keep your plan because of the Affordable Care Act,” said the group’s senior policy analyst Heather Hadley.

But now consumers are flocking to the website in droves. More than 2 million visited and 29,000 chose health plans in two days this week. That pace is not nearly adequate to cover everyone who got a cancellation notice, but it may pick up as the website improves and the sign-up deadline approaches.

What people see when they get online will vary widely, based on where they live, how much they make and their age. Many will qualify for federal subsidies available to people with incomes up to four times the poverty rate — or about $94,000 for a family of four in 2013.

But some people will pay more for Obamacare-required benefits that they don’t want or will have plans that both cost more and have higher out-of-pocket costs. Beneficiaries may also have fewer choices of hospitals and doctors, which means people losing existing coverage may have to change doctors.

“More comprehensive plans that allow more sick people to sign up for them are going to cost more money,” said Tim Jost, an expert on the Affordable Care Act and a professor at Washington and Lee University.

The cancellation fix

Plans that are canceled don’t necessarily have to stay canceled.

Obama three weeks ago offered a rare presidential mea culpa for the botched rollout and vowed to make good on his broken promise: “If you like your plan, you can keep it.” He announced that he would waive Obamacare rules so that state regulators and insurance companies could let people keep their plans through next year. But the ultimate decision is not Obama’s to make. State officials and the insurance companies had to go along with the suggestion. The uptake has been decidedly mixed.

So far, roughly 20 states have OK’d the extension policy, about another 20 have declined, and nine remain undecided, according to America’s Health Insurance Plans, an industry trade group. But even in states that allowed extensions, insurers still have to decide whether to offer the plans in 2014. A few plans, like Blue Cross in Florida and South Carolina, have said they’ll offer renewals. But overall, nationally there are no firm figures on how many health insurers will offer this option or how many people will take it.

Keeping the same policy doesn’t mean keeping the same price. It can go up significantly, as the McGrath family learned when it received an offer to renew after Obama announced the policy change.

“It’s about $90 more per month, but I won’t attribute that all to the [health] law. It goes up every year,” McGrath said.

The reprieve would be only for a year — meaning there would be more waves of cancellations.

Some insurers also have given customers the option to “early renew” their plans, locking in the same policy into 2014. Colorado Commissioner of Insurance Marguerite Salazar said this week that more than 95 percent of state residents hit with the cancellation notices this year were allowed to renew their policies into 2014. Those policies can’t be sold after Jan. 1, when new benefit requirements take effect, but they can be sold now and continued into next year.

People could buy or extend a plan in the individual market outside the new insurance exchanges that they really aren’t thrilled with and keep shopping or exploring Obamacare options during the remainder of the open enrollment period. Generally, people can drop a health plan in the individual market; they aren’t locked in for a year or two like a cellphone contract or an employer-sponsored health plan.

Going bare, paying the fine

Those who choose not to replace their plans have the option of going uninsured and paying the fine for violating the individual mandate. In 2014, it’s as small as it’s going to get — the greater of $95 or 1 percent of taxable income. That will increase to $695 or 2.5 percent of taxable income in the third year.

The penalty in the first year has been criticized as too weak to be much of an incentive. But most news reports have focused on the flat $95 penalty, not the share of income, which in many cases would be much larger.

Hardship exemption

At peak HealthCare.gov dysfunction in late October, White House spokesman Jay Carney said that anyone who doesn’t have access to Obamacare will not be penalized under the mandate for not buying a plan. The administration also signaled that it didn’t think that would be likely.

But people can be uncovered for up to three months without facing a penalty. So even if they don’t or can’t get insurance by Jan. 1, they still have until the end of the open enrollment period, March 31, to sign up for coverage and avoid the fine. But that does leave them with a coverage gap if they get sick or injured.

In addition, there are several ways to qualify for a hardship exemption from the mandate, including the death of a close family member, large recent medical debt or eviction. And anyone who would have to spend more than 8 percent of his or her income on exchange premiums would be exempt.

That hasn’t been broadly communicated, or the message hasn’t gotten through. Some of the people in the news with accounts of enormous premium hikes eating up their household income might qualify for this exemption. It would get them out of the individual mandate penalty, but that may be cold comfort for those who lost coverage they could afford thanks to the law.

So far, the Obama administration has not suggested that the early website woes or the cancellations would automatically be considered a hardship. That could change.

“The hardship exemption is defined through regulation, so the administration does have some flexibility to adjust that … but we’re still not far enough into the open enrollment period to pull that trigger yet,” said Sabrina Corlette, a health policy expert at Georgetown University.

Of course, that leaves people uncovered — which isn’t the goal. Some insurers do sell short-term policies, which offer fewer benefits but also cost less. Because they are short term, they don’t have to meet all the new Obamacare requirements. And they aren’t being aggressively marketed by the industry, an insurance official said. But agents do offer them, and they may help people bridge the next few months as they figure out the Obamacare landscape and work through the exchanges.

Catastrophic plans

Relatively cheap plans with limited benefits are available in the exchanges to those younger than 30 but also to anyone who receives a hardship exemption on affordability grounds.

It’s not clear how many people will take advantage of the option. The catastrophic plans have a somewhat higher deductible than most plans on the exchanges — $6,350 — and require people to pay it down entirely before coverage kicks in apart from a minimal primary-care benefit. But for many people, it’s not likely to be that much cheaper than the lowest-level bronze plan, said Larry Levitt of the Kaiser Family Foundation.

There is a bureaucratic barrier as well. To get a hardship exemption, consumers must apply to the exchanges, but that process is still being finalized.

The outlook

A lot depends on how the website continues to perform. If more and more people get confident and turn to it, it could overload HealthCare.gov, and it could crash all over again.

But some of the staunchest backers of the law remain confident that things are looking up. “I think the lion’s share of the people who are most in need of getting immediate coverage will be able to do so,” Ron Pollack of Families USA said of looming deadlines. “That does not mean 100 percent — because you never get 100 percent.”