In MA my chickens never had a problem with their waddles in the winter, it's was their combs that occasionally got a touch of frostbite, and just the very tips which would heal over come spring.
When I was in MA I used the heated dog bowls, similar to this. It's been almost a decade so I don't remember the brand, but lasted for the life of the chickens, 8 yrs:
Farm Innovators Model P-60S 1-1/2-Gallon Round Heated Pet Bowl, Speckletone Gray, 60-Watt...