Anyone looking for info on campsites/campgrounds on the TMB or for any other adventures in the area here are a few helpful guides:

http://www.tmbtent.com/guide-camping-tour-mont-blanc/
https://annapaxton.com/2015/08/09/tour-du-mont-blanc-camping-a-guide-to-campsites-on-the-route-of-the-tmb/

Hope this is helpful for anyone looking for campground info in the area.