What kind of coop do you have for them?
My ducks coops has hardware cloth on the front and back and tin for the roof and sides, so it's very well ventilated. When it gets very cold, we stack straw bales along the back so that the ducks have a windbreak. We also don't put any food or water in the coop, so it stays cleaner and drier.
I have cement mixing trays that we got from Lowe's that doubles as a bath/waterer. I do have another bucket for them just to drink out of, but they do love to swim and it helps them stay clean even when it's cold.
View attachment 2849210