Banty, I've never had any problems with my australorps, personally, and they are often suggested as cold hardy breeds. The hens never seemed to get those famous big combs, especially because I do not supplement light in winter. Their combs would get big and red in the summer and shrink down in the fall a little. They were always smaller than my Ameraucana rooster's comb come fall.

I am not too far south of the OP (I'm in NE Ohio), and get -10 easy every winter.
The leghorns, though, ugh. Those big combs and loooong legs are just the worse. D:
But hey, to each their own. Everyone's situation is different. The orp/lorps work great for me.