There currently are a variety of options to travel by night train from Briançon (France) to Paris (France), taking between approximately 11 and 13 hours: Namely the INTERCITES DE NUIT n° 5790 and the INTERCITES DE NUIT n° 5792. These lines are operated by SNCF.
The National Company of the French Railways (SNCF) operates a handful of lines throughout continental France.
SNCF night trains are equipped with standard seating carriages and couchette carriages offered in two comfort classes.
In the couchette carriages, you travel in 4-person compartments (first class) or 6-person compartments (second class). The berths are simply designed in both classes and are about 1.9 meters long.
Yes, for more privacy, entire 4-person compartments can be booked exclusively. This can also be done for a group.
First class berths are slightly wider than in second class and there are only four berths per compartment. Advantage of first class: In Paris and Toulouse, there are showers at the stations for first class passengers. In second class, six travelers share each compartment. For cyclists, it's possible to bring a bicycle in second class for an additional fee of 10 euros.
You should bring your own food as there is no restaurant on board. Alternatively, you can pre-order meals and drinks or eat before departure. First class travelers receive a small breakfast. Each passenger receives a night kit with refreshing towelette, dental cleaning tablet, sleep mask, earplugs, and water.