In a different part of France, we have been to Ile-de-Ré many times, and it’s hard to beat for a family holiday. Not too hot due to the Atlantic coast but very sunny, you cycle everywhere and it’s very safe (paths are almost all off the road). Food is good, amazing beaches, pretty villages to visit and loads of great campsites. You can fly into La Rochelle and bus/taxi to your campsite and hire bikes from there. Our kids have always loved the cycling through the forests at night with their bike lights!
Also, it’s still quite French in nature as it’s a popular place for holidays for locals too - which for me is a great thing - but ymmv.