To be clear OP given it seems to be relevant my teens are DSD and DS (half siblings rather than step siblings though).
I do get what you mean about the burden of cooking.
I'm the family chef (I enjoy it and apparently good at it - DH is useless and hates it).
That said whilst I do enjoy cooking a number of meals whilst on holiday (roaming the local markets etc) I too also want to relax in the evening.
I think non-cooks underestimate the mental load of cooking. The cooking itself is fairly easy - it's the thinking about what to cook, shopping for ingredients, then replanning again when they are not available.
I love walking around a local market and planning a meal around the produce available - but I don't want to do that every day on holiday. 3/4 times at most on a 2 week holiday. Frankly I do it every day at home and deserve a break too.
I think you need to look at a resort that has aparthotels or villas on a complex with loads of restaurants to get the best of both worlds.
We stayed in a Villa with pool at Aphrodite Hills, Cyprus (they have apartments and a hotel also) that has a massive "village" square with shops and 6/7 restaurants and loads of other activities (golf/sports/water sports etc).
Depending on budget it might suit.