When Stalemate is a Good Thing

Recently, I've been helping out with my son's elementary school chess club.  Many of the games there end in stalemate when one side has an overwhelming material advantage but doesn't know how to checkmate without first stalemating the other side.  So usually stalemate is a bad thing, a mistake made by the side that was winning.  Here in this game that I played over 20 years ago is something somewhat unique -- a stalemate forced by the side that was losing.

I think after 82. Qc5, there isn't anything black could do to avoid a draw.  Do you see anything black could have done then to win?  Or maybe a little earlier?