I'm in Michigan and can relate all to well about the cold weather, especially when Lake Effect Snow comes, my female Rouen laid her 1st eggs, 30 total! But only 6 that I'm incubating are vital, and she has 11 she just went full broody on 3 days ago, the other 1/2 were not fertile or died very early on because I saw the blood ring. This is the 1st time being a duck owner myself, and I was going to ask the very same question but everyone answered it for me just now, so thank you for posting this question, so what I plan on doing is bringing momma and her babies into our basement for the winter, as well as the dad, lay bedding down with wee wee pads and a heat lamp. We have concrete floors so it will take a bit more time and cleaning, but it will be all worth it to me. My girl laid for 4wks before she went broody,however I did take 1/2 of them away, I can't even begin to imagine her trying to lay on 30!! But she is being an awesome broody momma now, I didn't think it would click but it sure has and she is doing a marvelous job! I'm not expecting all 11 to be vital, but we shall see if she gets up and takes a break where I can sneak into the nest and candle the eggs. If you have a place that you can house them, I'd go for it. My 6 are due in separate dates, my 1 is due next weekend, the other 5 in the incubator is due late mid October, but if momma hatches these 11 eggs, they will be due end of October.