We plan to go directly from CDG to Lausanne by train but I'm not sure about connections. If I understand it correctly, I have two choices (1) take an RER from CDG to one of the Paris train stations (Gare de Lyon?) and then get a direct train to Lausanne or (2) get a TGV train from CDG to Lyon and switch there for Lausanne. If this is right, which of these choices is preferable, considering that we'll be jet-lagged and are first-time train travellers?
Also, when scheduling the train tickets, how much time should I allow to get our luggage, clear customs, etc. at the airport?
I would allow four hours between scheduled arrival time and the departure time for the train if you are taking the train from Gare de Lyon and allow three if you are taking the train from CDG. I suggest that unless you have a group that is larger than 2, you take the Air France bus to Gare de Lyon if you decide to go into Paris to get the train. The train from CDG is probably going to require a change at Lyon and at Geneva so that will be two changes so that is six times that you will have to move your luggage on the trains. However, depending on the timing, there are direct trains from Gare de Lyon to Lausanne so that would reduce the amount of times that you have to manage your luggage on the trains, which could be important if you have a lot of (or heavy) bags. My usual inclination is to take the train from CDG but in your case with two transfers to get from CDG to your location, I would check on the timing of the direct trains from Paris to see if they work with your schedule. If they do not and you are looking at one or two transfers if you leave from Paris, I'd just take the train from CDG.
Thanks for the comprehensive reply JHK.
I think we will take the Air France bus to Gare de Lyon, then a direct train to Lausanne. My recollection from other trips is that the excitement of being in France makes me forget about jet lag for a few hours, but that doesn't mean my judgement and functioning aren't affected. Therefore, the fewer transfers the better, and even those should be as close to landing as possible.
Thanks for the estimate of 4 hours. I don't want to be standing on line or sitting in a station as jet lag catches up with me, but it would be even worse to miss the train to Lausanne. The schedules could change as we get closer, but as of now there's a scheduled train departure about 4 1/2 hours after we land, so I'll shoot for that.