There was quite some fuss a few weeks ago about a company called Travelski claiming to run a night train Paris to the Alps ⛰ for skiiers, and from the coming season https://www.travelski.com/travelski-night-express

But I can find no evidence HOW they can do this, so I made a #BullshitMeter for it

Embarquez pour un séjour au ski plus responsable avec Travelski Night Express

Partez au ski sans stress et profitez jusqu'à 8 jours de ski avec notre offre Travelski Night Express. Offre : Train de nuit + Hébergement + Forfait + Matériel inclus !

(And yes, there is a SNCF night train to Briançon which you can use to go skiing, but the destination of this private one is supposed to be Bourg St Maurice to serve a lot of the much larger resorts)
@jon is the Briançon train/skiing nice? It sounds lovely.
@skorgu Not really, because that's not the best part of the Alps for skiing. But it is no doubt a pleasant (if slow) ride.