Along_the_Wire 8 ½ hours from St Pancras to Bourg St Maurice. Bout half hour shorter into Moutiers… Transfer from there is about ½ hour. Though as Bens points out, Eurostar aren’t running the Snow Train this year. It’s been chartered to TravelSki for the season, and you have to buy a package through them.
Last year, I did a Eurostar to Paris, then a TGV to Moutiers. Takes ½ hour longer, but a bit more of a ballache, having to transfer in Paris. Would still take that option ahead of flying though.
Last time we flew in and out of Chambery, the trip down the mountain took 7 hours. Fuck that shit.