Northwind, La Thuile is probably my favourite lift accessed riding, though like Chamonix I think it’s better on an enduro style bike than a full DH rig (I used to race DH, got 3rd overall junior in the old SCU series, which shows my age, so it’s really not that I don’t like DH!!!) It is a pretty expensive 40 minutes though if you have to pay the full whack for the MB tunnel…
Pila just a bit further (and many euro’s if you take the autostrada) down the Aosta valley is better for pure DH riding.
Hire a van and make a roadtrip of it! Start in Chamonix then Pila, La Thuile, over the col to the Tarantaise and its Tignes/Val D’Isere free lifts, Les Arc/La Plagne for singletrack, round via Beaufortaine and its buses, La Clusaz, Portes du Mont-Blanc, Grand Massif, PDS, return van, go home a hero!