@mouviciel brought me on the right track …
You can book the night train either via the dedicated website (only in French) or via the standard SNCF website, which is mutlilingual.
If you want to have a private 6-berth compartment, you have to be a group of at least 4 travelers. If you are less than four, you can only book 4-berth compartments as private compartments. This means that at the beginning of the reservation you have to choose first class, rather than second class. Then, when picking your train and your ticket, a special box appears, where you have the possibility to choose the “private area” option.
It does not always appear. Reading the fine-print it turns out that on some trains this possibility may not exist. And where it exists, there may only be a limited number of compartments available for this service.
It looks like it’s now available online (fr).
Credit:stackoverflow.com‘
4 Mar, 2024
4 Mar, 2024
4 Mar, 2024
5 Mar, 2024