Move hens and female duck in together for winter?

It would probably work okay. I've read of several people keeping chickens with their ducks (not to mention other animals). The two species usually get along together pretty well. The only concern is that ducks are messy and have a tendency to soak their bedding with water. That works fine for them, but wet bedding can get moldy and lead to respiratory problems with the chickens.

 

um i don't know ... i guess it could be okay but remember ducks can't really climb ramps and when they do climb it , it hurts, even if they don't show signs they are literally killing their joints, so i would be care flu of not letting the ducks go up the ramp unless you make it a bit more flatter like not so much of an incline. um also some chickens have been known to claw at ducks and ducks have been known to bite out chicken feathers so just look for signs, I'm sorry I'm pointing out the negatives, but hey at least you don't have muscovies because if you did the chickens wouldn't be around for long lol

 

One of my ducks lives with the chucks.
Manages ramps fine - I had to renovate their coop as the Campbell was flying up to where the chucks slept without a ramp and dropping down in the morning...
She does make the area under their perches wet and smelly as the days go by; but it just means cleaning it every week or 2.
It wouldn't work if either chuck or duck was unhappy with the situation tho!