I took some 5gallon pails cut a 6" hole in the bottom, upside down over a hole. Put my tip up s Through the hole no reel in water and keeps the hole from freezing over and snow blowing in.
Doesn't your line freeze together after a fish has taken some out and you wind it back up? It would still be ambient temp inside the bucket and that is almost always below freezing. Then the line won't go out when you get a fish right?
I know that is why I only use my windlass tip ups on warmer days.
I have read in a book( Tom Gruenwald?) where they show pictures of one solution. You take a short piece of 1/2" PVC and glue a small piece of pipe wrap foam around it so it floats. Slide it on your line and place in hole then you can add mineral oil to keep it from freezing. Your line would still freeze on the spool on cold days.
These tip ups can work great on warmer breezy days for pike fishing. I like it when it gusts slightly. If it is adjusted right it gives it a great erratic jigging action with occasional pauses.