Hi from another Canadian with Muscovy ducks. Mine do free-range all day depending on the weather. I have a 10 x 10 run off the coop I made by buying a portable garage kit. It has a tarp roof, I covered sizes with chicken wire, and made a door with plastic piping. One long side also tarped as wind block. They are happy in there on bad weather days, and it is where their food and water is. As for flying ability, I regularly find my 5 females sitting on top of my house (one story), garage, and vehicle. During summer, when there is lots to forage, I only give them their duck chow in the evening as an enticement to come back to run. Has worked well so far. With the ground covered in snow, they stay fairly close to home because I spread little piles of "scratch chow" for them to find. Only twice have I caught them heading up my lane. I circled around them and chased them back screaming like a crazy person and waving branches. Good thing no one was driving by at the time.