Are they laying down outside... or in the coop?
How high is your feeder?....trying to picture this.
Hopefully they are in the coop and/or protected from any wind.
Eating and drinking is good.
I look for mobility by tossing treats, if a bird is not moving well it may be cold stressed.
This is my experience with cold stressed birds:
@BantyChooks taught me about 'cold reset'. I bring bird into the slightly warmer garage for just a couple-few hours. Makes sure she eats, give her a dose of electrolytes, see what's coming out the other end, and just observe. Then take them back out to coop, has 'saved' a few here, it's pretty amazing how they bounce back.
Birds can get dehydrated in winter as well as summer, so I give the whole flock a dose of EL during really cold spells (<10°F), I just mix up a half gallon of Sav-A-Chick electrolytes/vitamins and put it out in a open waterer for a couple hours so they all get some of it. Of course plain thawed water should always be available, they won't eat if they can't drink.
This winter I soaked rolled oats in the SAC solution so no liquid to dip wattles in.
It worked great, had no seriously cold stressed birds. 1/8 tsp SAC powder to 1 cup of water mixed into about a cup or so of rolled oats.
If they
do have frostbitten combs/wattles, hands off is best IMO.
https://www.backyardchickens.com/articles/frostbite-in-sw-michigan.74597/
I have no experience with seriously FB feet tho...they may need attention.