Use 'search' to look for a couple of loooooooong threads from the past several winters, one on Alaska members and one on cold weather region coops in general. Evidently you are not in the cold part of Alaska though so you will also find much in common with BYCers in the northern tier of states and much of Canada.
You also might check out my 'cold coop' page, link in .sig below, for an overview of the subject and suggestions. I live about an hour north of Toronto, and due to being in a low spot our coldest winter nights are in the -20F range (yes, I'm giving you F numbers, not the local C <g>) and we have been down into the -30s F at times.
Choosing an appropriate breed is a big part of winter-hardiness. Also ensuring dry air in the coop, meaning good winter-appropriate ventilation.
Good luck, have fun,
Pat