Oh your about 2hrs away from me then. Its always sad to lose one. I've lost 4 in total and it was heart wrenching every time. I'm sure they will do fine just make sure to keep as much snow out of their house as possible. Along with helping them be as warm as possible.
Where abouts? I'm from Malone. Oh it must just look small in the pictures. Yes straw bales around the outside would be good too. No problem. As bluejeans has stated ducks are pretty tolerant of the cold but since my ducks and geese are like my kids I like to make sure they are comfortable as can...
I also live in northern NY. Adirondacks area. How big is their house? It doesn't look big enough for the 5 of them for the winter. As you know we have harsh winters and there will be days that they need to stay inside. I use straw or hay in their house as it helps them with heat along with it...