Simply taking the weeks off the already shortest holidays in Europe (together with Germany) will not help the teaching retention and recruitment crisis, nor will it be feasible from a financial point of view as the state already doesn't have the money to pay staff - it will be unable to finance 2 extra weeks.
Adding the weeks on to other holidays makes zero sense if the issue is the need to find ad hoc childcare (because that need will still remain) or holiday prices, because those will just rise, as will the weeks preceding and following them. Plus, who wants to holiday in February and October when it is damp outside, and often cold. If we're looking after our most vulnerable, that would disadvantage them even more, since they cannot just play outside, unlike a lot of summer.
The learning retention gap exists because many children spend their time glued to devices all summer long. Those who have actual experiences like holidays, exploration or socialising often come back not only refreshed but better equipped for learning. It's not just academic learning that counts, but all the other things schools cannot teach.
SEND children don't just encompass ASD children; they also cover all of those who cannot cope well with school mentally and who thrive in the summer, away from that place. Why do we advocate for one group. but not the other?
School buildings are falling apart as it is, and if you'e ever tried to learn in a classroom with building work going on next to you, you'll understand why the time for major refurb work falls into the holidays. That still needs to happen.
A PP mentioned exam marking - no one would mark those voluntarily if the time for that was even shorter.
With the amount of flexible working available now, finding the time to cover the holidays is easier now than ever before. My partner works longer hours term-time so we can spend more time together during the holidays. He does half-days where he can to add extra holiday days to his allowance. He works from home most days. This is becoming increasingly common.
Leave the six weeks well alone; they already far shorter than the time kids get away from schools elsewhere.