Same here we put bucket in box surrounded by straw, and hay most times that will keep it from freezing.I have never been brave enough to try heated buckets. Saw a barn burn once from one that was hung up in a wood stall. I use bucket covers instead to solve the freezing issue but here in TN it doesn't stay too cold too long.
If it gets to were it starts freezing smartpak has a really good bucket cover that I use and from where it was designed for new England winters I have never had to break any ice with it. I have one in each stall and so far so good. The filly and one goat likes to try to pull them off so if they get the side straps loose it will start to firm some thin ice at the top but pull the straps back up and there is no problem.Same here we put bucket in box surrounded by straw, and hay most times that will keep it from freezing.