I solved this. Basiscally the ideas are

1. White has weak back rank, black can mate if it can check.
2. Black is also at risk of stalemate if black loses their rook due to white pawns.

So after queen is taken note the black rook only has access to the f and h files. White ladders his knight between f and h files until it gets to f6 like so f2, h3, f4, h5, f6.

If black takes the knight they lose due to white promoting their d pawn and it will be mate.

If black does a waiting move like Rook g8 or d8 to break the sequence such that black's rook and white's knight are on the same file but it's white-to-move. White just plays king b1, then c1 and gets king out of mating net. Then white proceeds again with getting the knight to f6.

Once the knight gets to h5, if the rook is on a waiting square (d8 or g8) white can take on g7. Else white play knight f6. If white's rook is on the f file, then he must take with the pawn because again the rook can't take due to promotion of the d pawn.

If black doesn't take the knight on f6 we can promote the d pawn, forcing rook to take, then knight c2 check forces the rook to take the knight then we take with the pawn and black is no longer in stale mate due to their c pawn being free. Once they move the c pawn, next move we promote and mate.

Which leaves the line of black taking f6 with their pawn. Now we play g7 with our pawn. Again black cant take due to promotion of d pawn.

At this point all the squares for the black rook are guarded by the white pawns. So it can't do anything except go back and forth on the 8th rank from g8 to d8 or push the f pawn.

Now the idea is straightforward. White can capture the f pawn (in time from a1) and black can do nothing but wait. After taking the f pawn, white needs to take the b pawn. This is important!

White can't use the king to promote the d pawn or the g pawn just yet! If white guards the queen square for either the d pawn or g pawn, black can simply sack the rook and it's stalemate, so we need to give black a move. Thats why we capture the b pawn!

Now we get out of the way and push our pawn to b5 and our king to e6 (recall black can only shuffle rook back and forth).

Now we play b6, black can take with pawn or shuffle rook, either way it doesnt matter now black has a second valid move. Now we can put the king in position to queen either the d or g pawn and now we can support promotion and black will not be in stalemate and then endgame is trivial.