In reply to slinky wizard:
My sister owns a hostel in Bourg Saint Maurice. It's not Arcs 1800 but it's nearly opposite the bottom of the funicular that runs straight up into Les Arcs. The first funi is about 8am I think. I don't know if she has availability but you can try her. The number is 00 33 479007593. There appears to be another number on the website so you can try that too.
The website is here: www[dot]loftbourg[dot]com
Think there are prices on there. It's self-catering and she takes anything from one night to a season.
Rach
