I think I must have camels, not chickens!!
This is our second time having chickens (9 four years ago, 10 new ones since July 2020). The first time I paid very little attention to the chickens, they were my son's responsibility.
This time they are MY emotional support pets and I am spoiling them rotten!
Our nine chickens last time managed to survive three years on just snow throughout the winter ~ for each of the three winters that we had them, (which lends me to believe that yours are probably just fine).
I'm Canadian (and unequivocally suck at math) so I'm not exactly sure how much 4 gallons is, (but I think my husband said that our hanging water bucket was 5 gallons) so if your nine birds are drinking almost that much ONE DAY, my girls have to be camels and not chickens at all!!
Between the ten of them, they don't even drunk one full 9x13 baking pan in one day. (Even in the summer they didn't drink the whole five gallons, not even in a week, but they had access to water in their run, not just from the 5 gallon bucket in the coop).
We have had virtually NO snow this year. But below freezing temps meant I needed a solution, but fast!
Putting a 2L bottle of salt water in the five gallon bucket did NOT work, at all, and even if it had, the metal nipples froze anyway.
Just this past weekend, just in time for -21°, I asked my husband to make a cinder block heater, and it works WAY better than expected!!
And even though it was minus-minus cold that first morning, we even had to lesson the wattage of the bulbs from 100 to 60!
I'm so thrilled this worked!! Now I don't have to worry.
(Well, I didn't, until I read your post.

Now I think my chickens must be dehydrated too! Like yours, they seem to be normal, happy, active birds ~ well, except for the few -20°C days like we had last week, then they aren't happy)!
I'm attaching a pic of the cinder block heater, and here's a link to my post on IG if you're interested in seeing "in-progress" pics.
I hope your girls make out ok!
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