This year I stayed in an apartment instead of a mobile home, but I went to take a look and inquire. For such a nice ski area, this is a hopeless place. You are literally and figuratively pushed into the corner. You will not get to the sani station 8/10 times because it is full of cars and they flot bleu is located between the cars and skiing to the mobile home is not really possible. There are better locations to make places for campers, I think (hopefully people read this)

arrived April 26 late afternoon after skiing, wanted to stay for 3 days. No problem, pay at the cash register/reception and park. could no longer book on the site, were too late with that. (valthoparc.fr) they want you to reserve 2 weeks in advance. Furthermore, well stood, view is good. there is a sani column to use for €2. Tight blue and doable if you are completely self-supporting.