Similar position with white queen on b2 is even more favorable because d-pawn is pinned and White has one more tempo to execute winning. White always wins if his king is two steps away from key square c2, or one step away from controlling the squares d3 or f3. It means that winning area is bounded by squares a1 to a4, from b5 to h5, and further to square h1. It is interesting that Averbakh in his “Endings” omits squares on a- and h-files! With king on a1 White wins.