The Taxi + Cars Air France or just Taxi plans will work and will avoid the RER, but they'll also subject you to road traffic which can be hectic at certain parts of the day. You'll still need to be careful that you leave enough time to get to the airport to not miss your check-in time.
For reference, I always leave central Paris 3 hours before an international flight to be sure I have enough time should something happen with the RER.
Neither method is infallible; instead, you're best to choose the preferable one and leave a good buffer in case traffic or unscheduled stops hinder your progress.
Peace.