Well, clearly my water comment was misunderstood. Chickens need water to digest food, practically any food. Without that digestion they are unable to regulate their body heat in cold, and so without water, chickens can die in winter. It is not so easy for them to die in other seasons, as they typically do not need to generate as much heat in those other seasons. So, in winter, a chicken will consume a lot more feed to generate a lot more heat, assuming they haven't other ways to preserve body heat. Clearly they need water in all seasons, but they need a lot more in winter.
In an earlier post, I suggested that if you were going to bring in water overnight to help prevent freezing, then bring in the food too. My premise was simply that if they consumed food, they would naturally need water to digest it. Leaving food out without water to digest it makes no sense. Leaving food out would, however, make chickens eat it thinking they could digest it. Without additional water, they won't, or will but at a huge cost to them. So, pull water, pull food also.
This is by no means ideal. Do that during a warm time of the day and your chickens may not have taken in enough calories to keep them warm overnight.
Lazy Gardener caught me off guard, It said to bring in feed, which is all I was suggesting. Our premise may differ, but the results are the same, but it didn't say anything about how to keep fresh water unfrozen for chickens to drink. And there is one of the biggest problems of keeping a flock over winter. Bring in the food all you want, if you can't keep drinkable water available, things will likely fail.
All I tried to say was you have to keep drinkable water available more than edible food is available, as water is required to digest any foods.
Oh, btw, the idea that chickens are thirsty, IMO, is a human trait being ascribed to a chicken...they drink to digest food.