Don't worry about 0*F. I have a few weeks every winter where that temperature is the high for that time period. I don't use any heat in the coop. Healthy LF birds will be fine. Bantams, especially hard feathered breeds, might require some help, as well as any roosters... for some reason I've noticed they're faster to die than hens. Of course, if it's just a one-night thing, I don't think I've ever owned a bird that couldn't take that weather.Im mostly concerned about heat because there have been winters where it was 0 with a wind chill that made it -10.
It was -1F in this image... see, they're all fine, and even outside willingly! Birds are incredibly hardy.