It is not difficult to sleep at CDG in between flights, especially if you're inside Security. Terminals 2A and 2E are the most pleasant locations, whether taking a nap during the day or setting up camp for the night. Put on a sweatshirt and put your noise-canceling headphones on because it's probably going to be cold and bright wherever you decide to sleep at the airport. But if you would like to get a rather comfortable sleep, book a room at any of the multiple hotels at CDG.