A group of five, visiting the Loire Valley for 5 nights and Paris for 4 nights. We will arrive into CDG from Atlanta at 8:40 AM. The TGV to St. Pierre Des Corps leaves a 11:18 - 13:04 and 16:12 - 18:03. We plan to rent a car from Sixt at the station upon are arrival in Tours. I am concerned about delays through CDG with the new entry systems. We are also going in the middle of July, so peak travel season. I don't want to pick the late departure and have to wait around, but then I don't want to miss a train either. Any suggestions? I have never traveled through CDG but I have traveled a lot through Europe.
I think it's anybody's guess as to what's going to be happening in July. I know EES is being rolled out now and is supposed to be fully implemented entirely by around mid-April, so hopefully all the bugs will have gotten out of their system by July, but you never know. I think it's anybody's guess as to what's going to be happening at that time.
I would say you would probably be okay with a little over 2 1/2 hours, but that's easy for me to say. CDG can be a hot mess on a good day, so who knows what will happen in peak season with EES going on. It could change things for the better or worse.
I would generally suggest 3 hours between a scheduled arrival and a planned train departure from CDG. There are many unknowns, including the actual aircraft arrival time.
If anything happens, such as missing the planned train, I would take a train/taxi into Paris to Gare Austerlitz and catch the next TER to Tours/Amboise/Blois.