You can get these guidebooks:
Ski de randonnée Savoie, by E. Cabau, Guide Olizane Sport (Editions Olizane).
Ski de randonnée Isère, by E. Cabau + H. Galley, Guide Olizane Sport (Editions Olizane)
These two include all the mountain groups for like 20-30km or more in any direction from Alpe d’Huez. The second includes the section of the Ecrins mountains around le Berarde which is south off the backside of La Grave ski lift area.
About two lifetimes of ski touring (if you have a car to get to the trailheads).
If you want to start into that, some of us might want to join you for tours and share driving this winter and spring.
P.S. If that’s not enough, you could also get this one:
Ski de randonnée, Haute Alpes, E. Cabau, H. Galley, Guide Olizane Sport (Editions Olizane).
which includes tours around Col de Lauteret and Refuge de l’Alpe d’Arene and in the Pelvoux area of the Ecrins mountains.
and also this one:
Ecrins Nord (Toponeige)