Help with train reservations from CDG to Bordeaux

I checked, there don't seem to be any direct trains from CDG airport to Bordeaux in the middle of the day. SNCF cut a lot of those routes so I am not too surprised.
Therefore it makes a lot of sense to go to Paris first.
With an 8.15a landing, you stand a very good chance of catching the 12.11p from Montparnasse, which gets you to Bordeaux by 2.30p.
Or there is a very cheap Ouigo at 12.37p, which reaches Bordeaux at 3.16p. Ouigo have a 30-min check-in requirement, but you should make it in time.

Will it be worth the hassle of going into Paris after your flight to save an hour or two at the Bordeaux end? Possible flight and immigration delays could eat up some of your extra time at CDG. Is your first overnight right in Bordeaux, or will you have to get somewhere else from there that afternoon? My instinct would be to take the train straight from the airport and spend some of the idle time enjoying a late breakfast.

To me, it's not the time saving (which is minor), but the lack of a convenient direct train from CDG to Bordeaux that skews the balance towards going to Paris Montparnasse first. The 12:30 connection I see from CDG has a 45-minute waiting time in Massy. This, plus the likely waiting time at CDG to start with, is a lot of waiting around after a long flight. Sounds better to me to hop in a cab to Paris Montparnasse and "keep moving".

Purely a matter of opinion!

Appreciate your opinions and insights. Before making a reservation, I think I’ll keep checking, for awhile anyway, to see if more departures will be added, as Covid seems to be waning. We only have the day of arrival and next day to see Bordeaux and adjust to the time change before going to Sarlat to visit the prehistoric caves. We begin a 5 day cycling tour the day following the cave tour, from Bordeaux to Toulouse. Really don’t care to spend so much time waiting in train stations and on trains the first day after landing! However, the reality is not necessarily what I want or don’t want! Ha!

There is a train from cdg with a connection at massy at 1116 that arrives earlier.

Or you can book Montparnasse at 11:11 (arrive at 1317) and probably make it to the station in time.

You can also fly Air France from cdg for the same price at 10:20 and arrive at 1135.

Air France has several daily flights, about an hour, from Paris to Bordeaux. The flights look cheap but I would only do it if it were part of the trans-Atlantic ticket. That way, the airline, or perhaps airlines if it is in an alliance, have to worry about getting you to the connection.

We are actually scheduled to take the trains you mentioned after landing at CDG around 8:30am on March 23rd. At least there is a high speed for our return into Paris. My concern is getting the pass vaccinal that is required for public transportation. Does anyone know if and where you can get one at CDG? Thank you

Very helpful info. We found the journey from Gare Montparness and will most likely take that.
Flying to Bordeaux is still a possibility—and may work well from Toulouse to CDG, the final leg of our trip. Thanks everyone!

The journey at 11.11 am from gare Montparnasse is too early for an 8.15 am arrival at CDG. Take a later one.

It would definitely take a lot of luck! It might be prudent to pay the extra cost of a last min ticket…