In reply to J Whittaker:
It’s a pleasant walk up the valley before it steepens considerably. The latter half isn’t technically difficult at all, but is a bit of a slog! There can be some snow below the hut - no idea what there is this year. There are two possible places to leave from the car: the road out the back of Villar d’Arene and the Col de Lautaret. The former involves a bit more climb but is definitely more pleasant, and the difference really isn’t that great.
Timings for a “standard” party might be c4-5hrs. I’ve no idea where you’d lie relative to that, so can’t really comment further.
Definitely a great location with wonderful scenery. Lovely guardians too. Have fun!