I've booked a combined train + flight ticket with Air France, which involves taking a TGV to Paris CDG airport, then an onward flight. The TGV leaves very early in the morning.
I've been looking at the Air France page on TGVAir, and that says
If you are traveling by train to the TGV station at Paris-Charles de Gaulle airport ... Collect your ticket at the tgvair counter in an SNCF train station
To collect your ticket, present your trip summary or a form of identification.
Your Check-In Deadline is set at 15 minutes before your train´s departure time.
Since the TGV leaves very early, I'd rather not have to get there at least 15 minutes before to check in. I'd much rather have the extra time in bed! I'm also not completely sure that the ticket office will be open that early, and if it is I doubt there'll be many people there, so there's always the risk of a wait if there's someone there first...
Given that I'm travelling through the departure station the night before anyway, is it possible for me to check in then, and return to the station in the morning armed with my tickets. Is that possible?
(In case it matters, the TGV leaves at 5.57am, and I'd be looking to check in at something like 6.30pm (18:30) the night before, so less than 12 hours before)