I've never had a hen get frostbite even floppy comb leghorns, roos I've had get the tips of combs burnt but heal up come spring.What's the chance of frost bite on their combs and wattles? I have an Austra White and she has a fairly large comb. As long as they stay dry should they be fine? The low on Tuesday night supposedly at 8 now but it keeps changing.
If you have a roo with big wattles it's a good idea to set up their water so they can't dip wattles when they drink that can make for bad frostbite.
I just put a top on their water pan to prevent it.