Years and Years ago (at least 20) I remember a Mother Earth News article by someone who generally slaughtered all his chickens in the fall because he felt he didn't have the resources to care for chickens in the winter (didn't want to run electricity to the coop). That is, until late one winter he found a "stealth" hen in his coop who had survived all winter by itself, eating spilled grain and "drinking" snow. The author suggested that meant that people in cold climates didn't have to provide heated waterers, that chickens could survive, and even thrive (he said it was in blooming health).
My very first thought (I lived in NE Kansas at the time) was, well, that's all and good for people who HAVE snow all winter, but what about those of us that have a lot of freezing temps, but have snow on the ground relatively few days?
My second was, "how can you possibly miss seeing whole animal for several months? Was your coop in a different county??"
I can't imagine...
My thought now is...he slaughtered his whole flock every year?
(my memory is not that great but I don't think he was just raising meat birds, either)...
Anyway... my intended point was, at least some people have counted on chickens eating snow as a management tool. How successful that was in the long term, I have no idea.