Last year my molts didn't start until this time of year. My girls were not fully feathered until it was well into December. I live in NH, so we start getting cold weather about now, and it goes rapidly downhill from here. By December, the temps are typically freezing and below. My girls were fine. They seemed unfazed by the temps, although they did stay out of the rain/snow and wind more than they normally would. As long as she is acclimated to the cold and has no underlying health problems she should be alright until she re-feathers. You can give her some extra protein in her diet to aid in regrowing those feathers. It's worrisome when they are half-bald in the cold, but chickens are amazingly resilient and it doesn't seem to bother them at all.
Good luck.