my whole flock has decided to stay under the coop also. if i do make a path to the front yard only the older hens will walk through the snow the the front porch. And they will sit on the porch all day soaking in the heat (and pooping all over the porch). My banty rooster has decided it is warmer...
try making a path in the snow but leave about 2" for them to walk on. then put a bowl of goodies out in the snow and make a trail of goodies from the coop too the bowl. chickens are suckers for goodies.