There is no place in the US (and that includes Alaska) that is too cold for chickens. Trust me when I say they do just fine with little shelter outside at -40.
Think wild birds, they are the same as chickens but have less food and water, only the shelter they find, which generally is a tree.
They adjust to their surroundings, adding heat or keeping them warm makes them reduce their 'coat' so they suffer more. The best thing you can do for them is to get them in a cold environment, and keep them in a cold environment. And no day time high temperatures will not affect this. they react to extreme lows and highs which do not happen at the same time.
Think wild birds, they are the same as chickens but have less food and water, only the shelter they find, which generally is a tree.
They adjust to their surroundings, adding heat or keeping them warm makes them reduce their 'coat' so they suffer more. The best thing you can do for them is to get them in a cold environment, and keep them in a cold environment. And no day time high temperatures will not affect this. they react to extreme lows and highs which do not happen at the same time.