I would always carry with me (meaning not check-in) essentials in my carry-on. it happens too often that bags are delayed, especially with a long connection at CDG (plus another one in ATL). Even on point-to-point luggage gets misdirected or left at the departing airport. The few euros you spend at Bagages du Monde and the time lost is really worth it IMO. Vizualize yourself arriving in BKK after 40 hours of travel and without anything to change into.