Some companies would consider that if you applied under 'flexible working' laws, but you'd usually need to be employed first, then apply to change hours - and they don't have to accept if there is a good business reason not to, which I guess there usually is! I'm a careers adviser, so lots of my colleagues are on term-time only contracts having applied under our flexible working policy, but we go into schools, so it makes sense to have less staff on in the holidays.
From what I've seen in work, jobs like teaching assistants are pretty hard to get at the moment, so I'd do some voluntary work if you fancied that, but there are less popular jobs in schools like canteen staff. my mum was a dinner lady when we were little.
May be worth looking at university jobs as well as schools? Some I've seen advertised are not actually term-time only, but do have more annual leave than most jobs, with the proviso you take it in uni holidays, and I know my friend works in student support in a uni term-time only and part-time (but casual contract, i.e. no pay in holidays either, and uni holidays are long!).
Also, could you sign up with an agency for temp work - then you need only work when you want to, although no guarantees of a regular income.