My choice, for South of France - we have been in November - would be Nice. It won't be hot, hot, but pleasant enough to get out and about. An easy flight from City or Stansted, Nice Airport is almost in the town, just a cheap bus ride into the centre. Great Art museums, Chagall, Matisse, shops, restaurants. Trips by train to Monaco or Cannes in the other direction. No car necessary. Markets to buy your favourite French foods, and cafés everywhere. Apartments are mainly back a few streets from the Promenade so you wouldn't get a view. Antibes would be better for views, but not so much to do. Not too many English people in Nice either, you get the feel it's a working town.
Not for everyone, but we love it.