We are joining the RS Loire Valley tour on April 20th. Currently trying to get ideas as to ticket availability on SNCF. There are no direct trains showing on the schedule for April 20th, although the Sunday before(April 13th) shows many hourly options for direct travel. Can a seasoned traveler shed some light? We know that Montparnasse is the station to depart from and that we need to allow enough time to navigate the station with luggage, etc. Will the ticket options open 30 days prior to travel dates or some such parameter? Merci beaucoup!
You can wait a bit. There are no trains showing from Sat April 19 through Mon April 21. Could be a construction project and replacement buses are not yet scheduled, or the project could get cancelled.
The RS people can also advise as you get closer, since everyone on the tour will be having the same issue.
I ran into the opposite sort of problem in Easter 2023. I wanted to make arrangements to go to Giverny for Monet's Garden, checked the train times, booked my Garden tickets and checked about 2 weeks before and all was good for the train. Doublechecked on Thursday before Easter Sunday and there was a train to Giverny but none back to Paris. I called, went to the station and lo and behold there was no train back. Happy ending as I was going to be in Paris again November 2023 and the Garden allowed me to use my ticket then. So yes, there may not be a train.