Waiting to commute...
Join Date: Aug 2007
Location: Basel, Switzerland
Bikes: Number of bikes changing ...
i toured in the same region last year, magnificent... however, i was on my own and the bike a lot shorter than yours. i am from switzerland, so i took the TGV to get down to hendaye on the franco-spanish border. had to change trains in paris and cycle from one train station to another. no big deal though (if you have GPS). i remember i spent quite some time at the ticket counter to find a TGV that takes bikes on board.
what bothered even more is the lack of space in the TGV for bikes, it's hardly enough for one, space is cramped and the doors are pretty narrow. i doubt you will be able to bring your tandem on board entirely. unfortunately, if you don't want or cannot fly domestic, there's nothing much left. if you take the TER or IntercitÚs, they have more space but travel much slower and stop on every corner, and you have to change trains more often to get there. rent a car from paris airport and drive? 7 or 8 hour drive through a beautiful part of france.
good luck to you and enjoy the ride!