With foreign holidays a precarious business this year, self-catering rentals across the country saw a boom; at least if you couldn't get abroad you could "staycation" with family.
But some would-be holidaymakers are now being forced to cancel their plans.
From Monday, new rules will limit the number of people that can holiday together.
And it will deal "a hammer blow" to the sector, says Alistair Handyside, who represents holiday rental owners.
Under the previous rules in England, two families were permitted to meet if they observed social distancing measures up to a maximum of 30 people.
The new rules allow a maximum of six people from separate bubbles to gather.
Mr Handyside, who chairs the Professional Association of Self-Caterers, says after what has already been a difficult year, the new rules will bring yet more upheaval that could leave larger properties standing empty.
When news of the rule change came through at Best of Suffolk, its head of operations, Tim Ripman, admits the team "tried not to panic".
Out of 410 properties that the firm markets in the East of England, 118 sleep seven guests or more.
Until this week, the website boasted that their properties were perfect for large or extended family getaways, particularly "in a year where being together is what matters most".
So this is a "big curve ball" thrown at the business.
"It's going to financially impact us. Our largest properties generate the largest income for us," says Mr Ripman.
Best of Suffolk is contacting customers to discuss whether they want to adapt their numbers, postpone their holidays or request a refund.
"Hopefully there are ways to still offer them a holiday at the destination they've chosen, maybe down the line," he says.
Larger holiday rentals firms including Centreparcs and Hoseasons' owner Awaze confirmed that they would do the same - seek to rebook customers for a later date where possible, but provide a refund where preferred.
What are my rights to a refund?
The rule of six in England and Scotland has created one big problem for larger groups planning a late summer getaway.
With the new rules backed by law, there are relatively clear rights to a refund for those whose plans have been affected and have already paid.
Guidance from the Competition and Markets Authority says that consumers should expect a full refund if lockdown laws make it illegal to use that service.
Ultimately, courts would decide disputed cases, but the guidance suggests group accommodation and large birthday party bookings should be covered.
The consumer group Which? says that this should prevent anyone being left out of pocket for obeying the law.
Matt Fox, co-founder of BigCottages.com, which offers tens of thousands of larger properties, says there was a sharp drop in traffic to the website when the new rules were announced.
"It's a real shame," he says. "The sector was just starting to find its feet again and had the rug pulled out from under it."
Image copyright Matt Fox Image caption "My sister has three children, we have two. We can't get together."He says he accepts the government needed to act in the face of a growing number of coronavirus cases, but he doesn't think the "blanket rules" make much sense.
"A self-catering rural holiday with two families mixing seems as low-risk as you could get," he says.
It strikes him as inconsistent to allow people to mix in the pub and fly overseas, while he can't go for a weekend away in the UK with his sister's family.
Alistair Handyside says for smaller operators like himself, the rules could make the business uneconomic.
Last winter, he spent £250,000 converting a barn on his property in Devon that sleeps between 20 and 32.
While he has two smaller cottages he can still let, the larger one is, for the time being, a very expensive "white elephant".
He says what matters now is what happens over the next few weeks in the run up to the festive season.
"If we don't get December with Christmas and New Year, which are peak weeks, we will see carnage, we honestly will."