We have just got back, u r in for a good time. I did the tourmalet as well long climb. 26degrees temp at bottom, 3 degrees at top!
There are loads of small campsites in that area that are not on any maps. It is just a case of choosing your area and then the campsite closest to it. Some have pools as well which will be a bonus. Careful though, as the French go on holiday in August and everything will get very busy and cost more.