it's a question of CYA with the manufacturers, and it'd definitely be better (traction patch wise) if you ran those 215/45/16's on 7, 7.5, or 8" wheels, but you can get them on 6.5"'s and they're not going to pop off.

i know guys running 225/45/15 tires on 15x6.5" wheels for road racing events, and the tires aren't popping off the bead.