I have always managed school holidays so far with a combinations of annual leave, holiday clubs, grandparents and cleaner providing childcare for my dc. Having a variety works well for us - doesn't overburden the gps (who do not live near enough to come every day, the dc have to stay overnight) and isn't too horrendously expensive.
The eldest is now 12 though and holiday clubs only go up to age 12 - but I really don't feel he is old enough to leave at home yet in charge of younger sibling.
What do others do about this? We are at private school so have extra long holidays to cope with.