I just wonder how safe it is to use a calf hutch for wintering the waterfowl. I suppose you would have to construct a predator proof fence rather than try to seal up the hutch itself. The chickens get wood, the ducks and geese get the tin. The tin huts are set up on pallets and are bedded heavily with straw. When they get cold they go in and keep eachother warm.
Waterfowl tend to be pretty hardy birds in the winter anyway.
For predator proofing, I strung a strand of e. fence a foot off the ground about a foot away from the main fence, and then another wire about 6 inches off the top of the main fence. I fell asleep before turning the charger on. My fence is powerful to knock a cow down, but doesn't use up much power. Nice thing really. I know I've been lucky so far, I don't want to risk it much longer.