Arr CDG 830AM Thurs, Oct 2nd. Assuming flight on time: time it will take to clear customs, no checked bags, & get to Gare D'Austerlitz? Also best way to get there : RER train to St Michel & transfer to metro or taxi to the Gare? Hoping to catch the 2PM train to Chateauroux. And if flight late, are the pre purchased tickets exchangeable? Thanks.
The plane would have to crash and be rebuilt from tinker toys and duct tape to be so late that you won't make it. Worst case with immigration and everything else, you'll pull into Austerlitz by eleven. Switch to the RER C at St Michel / Notre Dame and it'll be quicker and easier. Total transit time is right at an hour.
Well, Ed, we are flying Delta! Seriously, thanks for the reply & the RER Transfer suggestion! That really puts my mind at ease, so I will get the reservations made tout suite!
Note that I skipped answering about train ticket refunds - - due to lack of knowledge. Somebody else will catch it.
An essential tool for using mass transit in the Paris region is http://www.ratp.fr/en/ which is full of tourist information and somewhat intricate trip-planning tools. Also useful and easier to read is www.Parisbytrain.com
Whether the tickets are exchangeable depends entirely on what type of ticket they are. If they are the low-cost Prems tickets, then they aren't and if you miss the train you will have to pay full fare.