c7 Bxc7stalemate.
really funny position! Win or draw?

Maybe I'm just slow, but why doesn't this work?
1. c7 nfd6
2. c8=B (Or Q or whatever) Bd4!
BxB7 isn't Checkmate, and Nxb7 isn't stalemate because the bishop isn't guarding b8 anymore.
Obviously there are a bunch of variations white can play out, but with the huge lead in material it's a clear win for black.
So what am I missing? : D
Draw. I saw it in CL4K.