I’m heading out to walk the Tour du Mont Blanc with all the variants in late August/early September. For the most part I’m camping “proper” in the valleys but will have to spend a few nights out wild on the hill if I stick to my plan. Trying to keep my pack as light and unbulky as possible to conform to airline rules, so wondering if anyone has done anything similar later in the season and can advise whether one, two or three-season bag is most appropriate. Thanks!