Which terminal? I don't think any of the terminals have a transit hotel. T2 doesn't but there is a Sheraton closeby (and on top of the rail station for terminal 2). You can walk there or take the shuttle bus.
If you can check your bags through, you could always go through immigration and take the RER into Paris. Not sure how much a simple rail return is but one return combining metro and busses is FFR 100-110 (in June).
www.adp.fr