Update: my winch cable froze solid during the January cold snap in Duluth
Three weeks ago it hit -18 in Duluth and my winch cable turned into a stiff rope, so I couldn't spool it back right after pulling a buddy's Ranger out of a snowbank on Highway 53. I ended up leaving it unspooled in the garage overnight, and by morning it had thawed out and wound up fine, so now I'm second guessing if I even needed to worry. Does anyone else just let theirs thaw out, or am I asking for rust doing that?
That "left it unspooled in the garage" move is probably what saved you, since getting it warm and dry quick is the whole game. The rust risk is real if you keep doing it though, so a light coat of grease on the cable before the next cold snap would let you keep thawing it without paying for it later.