In reply to HardenClimber:
As I'll be there at that time, happy to share my guess. Which is just that, a complete guess.
I reckon the snow line in mid june will be between 2,500m and 3,000m. All roads open (Ailefroide is already open, past Ailefroide and close to Pre. By mid June i guess it will be open all the way to Pre de Mme Carle). B2s, crampons and ice axe needed for most stuff at altitude that one would be able to do in approach shoes on drier years.