For what it's worth, I biked up the Col du Tourmalet in late May in 2004, starting in the village of Ste-Marie-de-Campan (I had cross the Col d'Aspin the previous day) and ending in Pau. Going westward, it was downhill from the col all the way to Lourdes. Sunny and warm day, the snow was gone, and coincidentally, it was the day the "géant du Tourmalet" (a statue of a giant cyclist) was being brought up to the pass for the season. Hundreds of cyclists from nearby France & Spain were climbing up both sides of the pass that morning, an annual ritual for when the giant returns.
I've never had any problems finding a room while touring in France in June or September. I haven't made any reservations other than for Paris.
I'll try and answer any specific questions you've got. From your initial post, it's not clear what you would like to know.
Last edited by axolotl; 10-30-09 at 10:57 AM.