I would like to use dog bowl but I don't think it will work I have the 5 gallon waterer so I USA fish tank heater but on cold nights the drinking part freezes
I use heated dog bowls every year - even outside, they don't freeze. When it was minus 25, I got a ring of ice around the outside, but the water was still unfrozen.
I have to chip out bottom of mine I think dog bowl is to small