I'm usually in ski boots so don't know about specifics, but both IME and Ragged Mt. in N. Conway have large inventory of plastic hiking boots in their consignment shops.
Merral Winteras are my boot of choice. Last winter was my first go with them and they worked great. They took my crampons, they where plenty warm, and the best part they never felt frozen in the morning.
I hike in Columbia Titaniums ($80) that are two sizes bigger than my leather summer hikers. I add an extra thick footbed and wear super-heavyweight wool-blend socks, sometimes with a wicking sock liner.
Ignore the shoe salesman. My feet don't slip around at all.