Happy hen lover
Free Ranging
That's ingenious! That's a bargain considering the time it takes to DIY one yourself.If you search the articles you'll find quite a few ways to keep a waterer from freezing.
After looking at the costs of everything I'd need to make one myself I decided that I will probably get one of these from Premier 1 because it's only a little more expensive and my time has value too.
https://www.premier1supplies.com/p/heated-poultry-waterer?cat_id=141