Don't know if this will work for you, but . . .
I made two, 2 gallon waterers, and put bird bath deicers in them for winter. I LOVE them - I can go about 7-10 days without having to mess with them at all (16 chickens). I've seen folks use 5 gallon buckets, but I don't feel like hauling 5 gallon buckets full of water, so . . .
They stay clean and don't freeze (Central NYS)

. We live up on a hill and it can get wicked cold up here, so we'll see. It's rated for -20F in an open bird bath, so I'm guessing having a sheltered, deep water bucket would up that rating a bit.
I like that the bird bath deicers just keep the water from freezing and don't heat the water. They're only 50W, and have a thermostat, which also makes them cheap to run. Reading here, some were concerned with using an aluminum heater in the water. The deicer I chose is enamel coated, so hopefully not a concern.
The nice thing about this setup is that I can just take the heater out when the weather breaks, put a lid without a cord hole on, and have easy, clean waterers for the rest of the year, too.
Don't forget to drill an airhole or two!
Ingredients

:
2 Gallon food-safe bucket and lid from Lowe's
6 Chicken nipples (you can do fewer if you like)
50W Bird Bath deicer
Drill and bit
Sharpie
Link for Chicken Nipples (comes with instructions):
https://smile.amazon.com/gp/product/B07DVM6RC9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Bird Bath Deicer:
https://smile.amazon.com/dp/B0006U2FJ8?psc=1&ref=ppx_yo2_dt_b_product_details
Hope this gives you some ideas!