On a whim, decided to check the Pech Merle website just now to see if tickets were available for when we are in the Dordogne late August. Was I ever shocked to find that not only was my date of choice open, but that we had the option of two tours in English- 11:15 and 2:15!
It appears that the calendar has opened up for summer. I hope this helps all forum followers who are visiting the Dordogne and hoping to snag tickets for a Pech Merle!!!