First, Le Petit is a great choice for a hotel, provided they have space. Have you checked availability? They are pretty small, so often book out many months in advance. As far as restaurant choices in Grand Case, unfortunately, most of the water side restaurants are NOT open. However, there are plenty of wonderful options on the land side. I assume you read the one thread that listed everything that is open? And, just because you stay on the French side, doesn't mean you have to dine there also, at least not all the time. There are plenty of wonderful restaurants on the Dutch side now. As far as timing, we go almost every year in June, which is not much different than July, as far as weather. And there are less tourists than high season, which is a big plus, to me. It might help to know what other islands you are considering.