I have fed liquids to my bees in the winter by placing an empty super body on top. You can use hive top feeders that are enclosed under your top cover, jar or baggie feeders. Bees need more than sugar to survive a long cold winter. I feed mine a mixture of soy flour, brewer's yeast, skimmed powder milk, pollen and granulated sugar. You can give this to them dry or mix these with a 2/1 sugar syrup to make patties. Good luck with your ladies.