Massif Central (especially le Puy but you seem to be going further east than that) and Provence (esp gorges of verdun and the Var, but you will probably be heading further west than that) were my two favourite sections in my first ever tour from Nice to St Malo ( I bailed at LImoges though
). If it's hot I'd just set off early although escaping from a locked camp ground in the early hours can be a challenge! Main warning is that there will be a few places without so many shops/ campsites etc eg parts of the Massif Central but a little preparation will sort you out. It's not like Northern Scandinavia where more serous planning is needed!