Hi, Zesty108,
While many have assured me that runner ducks can manage the New England cold just fine with enough dry insulated housing, I found last year that two of my runners are just not that robust. From that I have concluded (guess, really) that it depends on the duck. It also depends on the duck person's own comfort level. Don't make yourself a nervous wreck just to live up to someone else's idea of duck management.
My solution, part 1: First, take the ducks to the vet and have them checked out. Her observation: Your ducks hate the cold.
My solution, part 2: Since I have a walk-out basement, and plenty of room in it, set up an indoor pen for storms and freezing temperatures. Done and done.
They still spend most of their days outdoors in their pen, which is attached to their spring/summer/fall house and porch. That works very well for us, and I am home soon enough most days to get them into the basement pen before dark.
When I cannot do that, I either arrange for someone (neighbor, friend) to move them from the day pen into their indoor shelter.
I have nine runners. The basement does not smell bad. I refresh their straw daily, manage the water carefully, and once a week or so replace the straw altogether. It makes such good compost!
So now that I have written all about me and mine
have you seen any indication that your duck is too chilly? By the way, don't wait until the duck is suffering to bring him in - if it will make you feel better, make the duck a little spot in the house that's safe and easy to clean.