Will odd chicken out be able to keep warm in winter?

[drymanhattan]

I have four young hens in a coop with two roosts, one slightly lower. My polish hen roots alone on the lower rung while the other three (Rhode Island Reds and an Orpington) cuddle together on the upper. I am worried that she won't be able to stay warm in this unheated coop come winter. Should i remove one roost? Move them closer together? Or will the cold drive them together?

 

[Mrs. K]

In my experience chickens become much more accepting of other chickens in cold weather.