In reply to mike lawrence?:
Personally I would avoid the Envers in May, too snowy on the approach, possibly maybe snow patches on the rock above affecting the routes & therefore the pleasure.
Maybe the below in the Argentiere basin would fit the criteria, although he may whinge about the walk in to the Argentiere hut as the lift will not be running.
Versant Satanique (ED1 6b+)
Or right along side it & maybe better:
Voyage en Pierre Sainte (ED1 7a)
Both classic routes & as a acclimitisation exercise, you could climb the easier but just as good a route:
South-East Spur (TD 6a)
Sure you would have the hut to yourself other than maybe some steep skiers, but definitely the makings of a memorable trip.