Many tourist areas lost a lot of money last summer they need a decent turn of cash this year or you'll be killing thousands of jobs elsewhere.
Cut the summer vacation to two weeks, with the timing of the two weeks to be staggered among regions (any time from the start of June to end Septemberexample: "South Yorkshire gets its school summer vacation in the last two weeks of June"). Let people know as soon as possible when their two weeks will be, so that they can book. People can go on holiday during their two week slot (assuming that they even want to-some people will not be holidaying no matter how long the kids are off in summer).
A six-week summer holiday is not required to allow people to go on holiday trips---almost nobody goes away on a trip for more than a week or two!
Fines for those who do not comply because they want to take holidays at different times. I think fines should be lifted for those who are withdrawing for school due to virus worries, but taking kids out purely for holidays should not be allowed this year, assuming that a short two-week summer break is permitted. Disadvantaged children face a compromised future unless they can make up for learning losses incurred this year and last year.