We use a 4gal. black rubber hog bowl for the turks. Have it up on a milk crate (some heat loss there), keep a section of plywood over the top of all but about 5" of one edge (just enough so they can dip their beaks). Dumped (rubber bowl not plastic - can flip the ice filled thing over and kick the ice free without cracking the bowl) and filled in the morning it will stay `drinkable' slush or thin layer of ice forms around dusk that turks poke through when the temp. is around 10°F and it is cloudy. Have tarps over W/NW fencing so don't have to worry about the wind cooling it.
Use a smaller two gallon for chooks, in run, (sits down in straw), rock on plywood so they can't perch and poop, pretty clear for around four hours. I'd guess using the largest capacity container in the coop possible, and keeping it almost completely covered (4"-5" open for drinking), would surely help (place brick or other heavy object on cover so it can't be moved by chooks).
Our turks hardly ever eat snow, the chooks do (when water is available). I think they get set in their ways early on (our chooks think a whole, fresh, tomato is a threat and won't leave the coop if there is snow on the ground unless there is straw over it. Other flocks of chooks destroy whole tomatoes and plow through the snow without giving it a second thought.