Arriving at CDG and getting a TGV to Nantes

That is cutting it too close if you are planning to buy the ticket in advance.

The TGV tickets are all reserved seats so you would not be able take the 12:38 train using the 11:15 ticket without exchanging it online or in person for the 12:38 train.

And that exchange would depend on if there are seats available.

Also if you buy for the 11:15 train you need to buy a ticket that is exchangeable and refundable. These are the higher price ones.

You could buy an exchangeable ticket for the 12:38 train and then if you get through immigration and customs fast enough you could exchange it for 11:15 train if seats are available. Having checked luggage really slows you down in situations like this but sometimes you just need to check your bags. Also, it depends on how many planes are arriving at the same time, but my experience has been that the morning from 7:00am-10:30 am can be rather crazy busy at CDG.

Have you considered flying directly into Nantes? Nantes has a well serviced airport that many of United’s partner airlines fly into. It’s so much easier than trying to get off a plane jet lagged and trying to negotiate train travel. Nantes has direct flights from many of the European hubs like Amsterdam, Zurich, Frankfurt and Paris so please don’t limit yourself thinking you need to fly into Paris first to connect to Nantes.

Only an optimist would trust that exchanging a ticket for another time is guaranteed to be fast and easy. Line-ups at the CDG train bureau can be long and slow.

Regarding the comment above, ticket exchanges can be done on an app or at a ticket machine, no need to line up!
But I would aim for the 12:38. More reasonable.

If you are flying business class, you should be able to make the 11:15. We've made the connection in an hour but from business class and with EU biometric passports, so no passport line. . If you are in the back of the plane and your luggage doesn't have a priority tag, you could possibly make the 11:15. To be more sure, and just give yourself time to dawdle, stop for a coffee and croissant, use the toilets a few times, aim for the 12:38.

I fly today -- my plane is already leaving an hour late. This is not rare. I would not buy a ticket in advance for a tight connection unless you are comfortable having it disappear while you are in the air.

Thanks to everyone for your suggestions! They were very helpful. I think that I will just try to fly to Nantes and skip the train. We love to travel by train, but it is less hassle to stay in the air, and overall, cheaper. If that is not available, we will wait for the later train. I think we can exchange our plane tickets without a charge.

Thanks, the Forum was perfect!!