In the supermarket (Auchan/Carrefour) you would find it with the long life milk as it's all UHT
Looks like this and costs around 2 a bottle
http://www.lactel.fr/chacun_son_lait/chevre.php?b=3&c=4
You wouldn't find any fresh unless you went into a healthfood shop,and even then it could be tough outside of a large city, or of course directly from a farm
You could contact the hotel but be prepared to bring your own maybe powdered version as it's not an easy thing to find or for people to want in the mainstream