In reply to Heddwyn: hi, are you the guys I've offered a lift to? How are those dates looking, let me know, Ill keep you 2 spaces.
Anyway, it depends on the route and how snowy the season is, for most routes in the aig rouges you wont need crampons for the approach, maybe an axe if it's snowy. Similarly the M and petit charmoz are unlikely to need snow gear. Other routes might do/definitely will do depending on the route.