This morning it was 9 degrees here in Iowa. My girls always greet me at their door and are ready to run outside - on their hay path! I scatter hay around the door and on a path through their paddock to the gate. Morning and night I throw dried mealworms and scratch, and they get their fix of dancing outside. If we have several frigid nights in a row, I coat their combs with Corona ointment - they enjoy the massage. Once they have eaten the hay bits they like best, I scatter some more - they love it when I bring a flake that has lots of leaves in it. I have a net-covered paddock (previous jenny/foal pasture), and an enclosed coop with a raised, enclosed roost, so they have lots of choices both day and night. If I can open up the gate for some free-ranging in the late afternoon, they all head out, even over the snow. Trust your chickens to let you know what they will tolerate.