More work than @Beekissed 's suggestion. Never tried that, don't know how you keep their wattles out of the water in a dish.
I've always used open waterers in the winter, heated and unheated, and never had an issue with wattles in the water getting frosted. Not sure why so many folks have this problem....could be due to the fact I elevate my watering dish so that they aren't bending down to drink but reaching up and over it, so the wattles get held back by the edge of the pan.