Train from CDG to Dijon

You have to change in Lyon if you leave from CDG. There is no direct service from CDG to Dijon. If buying in advance it is best to get a refundable ticket, since you never know if the flight is going to arrive on schedule. I think it is easier to catch the TGV from the airport to Lyon and to connect to Dijon than taking a taxi from the airport to Gare de Lyon.

Thank you very much for your response. I have been reading about both train stations. It is hard to decide which would be harder for us: making our way through a crowded Gare de Lyon, but having only one train to get on and off or getting on the train in the airport, getting off in Lyon, going down and up stairs and getting on and off another train. I probably should have planned a completely different vacation!

To change train platforms in Lyon, you have the choice of escalators, or ramps, or elevators. If there are stairs, I’ve don’t remember seeing them. The station waiting area at the bottom of the ramps/escalators is fairly crowded. When you go back up to your second train, the controllers are at the bottom of the escalators to scan your ticket before you go up to the platform. We've never had a huge crowd all at once trying to get to the platforms in Lyon.

If you take a taxi to the Gare de Lyon, you need to orient yourself once inside the station. You look at the departure board to see if your train is leaving from Hall 1 or Hall 2. Follow the signs. Find your platform. Scan your ticket to pass the gates. If the train leaves from Hall 3, you have escalators or elevators, but I’ve never left from Hall 3. The station is crowded, too.

In Paris there are always crowds at the scan gate when the track is announced, but it thins out after a few minutes. A controller will be at the gate can help you if you have difficulty scanning your ticket.

The easiest way, in my opinion, is to take a taxi to Gare de Lyon. You will most likely be dropped off by the clock tower near Hall 1; once inside, a big departure board will tell you where your train is leaving from: either Hall 1 (right where you'll be) or Hall 2 (at the end of a gallery, off to the left then right). No stairs involved.
Taking the train from CDG to Lyon, then back to Dijon, involves a lot of backtracking, is usually expensive, and requires a transfer at Lyon Part Dieu which is a thoroughly unpleasant, overcrowded place.

If you take a taxi to the Gare de Lyon, you need to orient yourself once inside the station. You look at the departure board to see if your train is leaving from Hall 1 or Hall 2. Follow the signs. Find your platform. Scan your ticket to pass the gates. If the train leaves from Hall 3, you have escalators or elevators, but I’ve never left from Hall 3. The station is crowded, too.

Hall 3 is just an underground passage below Hall 1 & Hall 2, there are no trains there but you can reach both halls.

Personally I think it's a lot easier to take two trains, changing in Lyon, than to get yourself from CDG to Gare de Lyon (not a direct RER journey), then train. Be aware that there are two major train stations in Lyon, Part Dieu and Perrache. You are much more likely to use Part Dieu, but double-check that your first train will leave you at the same station that your second train leaves from. Some trains go to both.
Part Dieu can be very crowded at times like holiday weekends, but it's manageable. The only time I've really suffered there was during Covid when they had to check your Pass Sanitaire before you could get on a train. That was slow!

We take trains between our home in the south of France and either Gare de Lyon or CDG about once a month. Coming home from Egypt in January, we had this same choice, and chose to take a taxi to the Gare de Lyon and one train. We allowed plenty of time, had an early dinner across the street before boarding a late train home and were able to relax. It was uncomplicated which is what we wanted.
My first response in this thread, I gave no opinion and only describe the stations in order to help you decide, but then Balso reminded us how all the tracks at the Gare de Lyon are on one floor, unlike the CDG station and the Lyon station where you take escalators or elevators to reach the tracks. Then, the taxi is door to door. Someone else does the driving, traffic jams, and there's no schleping. So that’s why we took a taxi into town and the train from Gare de Lyon. I prefer the simplification. We're in the same age group.

I'm your age too and for me the Gare de Lyon option would be far better. The taxi will be expensive but easier than any other option, especially with luggage. Then one train from a one-level station. Since you could encounter delays in landing, CDG processing, and the taxi ride, I'd suggest leaving plenty of time before your GDL departure. A refundable ticket would be a good idea if possible. There are enough Paris-Dijon trains that you'd likely have a backup in case of too much delay.