A place you might look for fish in a lake is if you can find an unfrozen area with a steep drop off & some sort of structure such as rip rap or a sunken tree & then fish it with a good sinking pattern such as a clouser minnow. My best luck for late fall crappies came in just such a place. I fished the fly just above the bottom & used a hand twist retrieve. I watched the line carefully as the hits were usually pretty light. When the line tighten up a bit, the tip of the rod bent a bit or something else happened I set the hook & usually was rewarded with a crappie. They weren't big but they were FISH.
Good luck with you winter fishing!