I made super winter covers a few years ago. Took cross country socks that come up over my calf and cut out for my cleats. Put my shoes covered in plastic bag and stuffed with socks inside. Then took the black rubber sealer available from cobblers (comes in a ~4oz white can. and coated the bottom and coated the sole of the socks, going up about an inch around the edges.
This takes a while to put on. I put my feet in produce bags (to keep my socks dry, then my normal socks, shoes, a produce bag over my shoes, then the big socks. Makes the entire shoe part of the insulation package. Completely walkable on slippery surfaces. And they have a fun Christmas look about them, offsetting my black tights and the rest.
Ben