There will be a lot of being indoors, for weeks sometimes. Having things to keep them entertained is a big one, I used a slice of alfalfa but others use squash/apples/lettuce that they saved from their gardens. Also investing in some type of heated waterer/heated base will be a lifesaver. I myself use the metal fount and the heated base that you can find at runnings.
Having ventilation that goes over there heads but wont chill them will help to prevent frostbite, though you may have to just expect that you will get some anyway. I'm not sure what others do, for the most part I only have brahmas and other short comb varieties, but last year a light Sussex rooster and a few red star hens I had, all got frostbite. It was just a really miserable winter last year though too.