I do like these “take the latest and biggest things you can to the alps or you’ll die, or maybe just not enjoy yourself” threads.
I’m going to sound old here but, the first time I went to Morzine I was on a 140mm travel Patriot with Tioga DH 2.1 tyres and rims brakes. I think the bars may even have been less than a metre wide.
No matter what you take it’ll be a blast and, unless you’re travelling with very fast, very impatient DH’ers, subtleties of equipment really won’t make that much difference.
And FWIW, 2.35 swamp things are great tyres and, whilst you won’t win any uphill races, you’ll be fine on them everywhere else. Given the unpredictable weather and range of terrain there, I can think of a lot less suitable choices.