1. EasyJet flies to CDG3 (previously called T9), the charter terminal, which they claim 'is walking distance from the train station.' IIRC, the distance is indeed reasonable. Dress warmly

2. The Air France bus is definitely not free, except for people connecting between CDG and ORY on connecting AF flights. €10/11.50 to Etoile/Montparnasse, stops running at 11pm.

3. The public bus, Roissybus, stops running at 11pm.


This flight is cheap for a reason... Any way you could take the previous flight (arr. 21:45), which is usually inexpensive as well?

I would say you have plenty of time to make it to the RER station provided your flight arrives on time. It being the last flight of the day, it is at the whim of any delays accumulated during the day.