In reply to Mark Haward:
+1 for Le Tour glacier via Albert 1er hut. Aig du Tour, Tete Blanche, Petite Forche all in the grade range. Bivvy shelters on the col du tour if I remember.
Another option is to take half the Grand Montets lift to Lognan, then walk up to the Argentiere glacier. Bivvy spots on that side (i.e. river left). Petite Aig Verte via the Demi Lune would be doable from there (slightly longer than usual!) and Aig Argentiere. I haven't done the Tour Noire further up the glacier, but I've heard reasonable reports.