Haha, you guys are such engineers, fixing things that aren't broke! And I mean that with the utmost love and respect.
My solution is simply give them a little fresh water that they drink all of. Nothing sitting around to freeze, and no carrying big pails of water to refill a big empty basin. I can imagine some awesome frost free setups but my solution requires no trips to the big box store.
"Knowledge is power. Arm yourself."