I think so too. We had that super cold weather well before snow cover arrived, and that was probably a big factor. The lines to my washing machine froze early and often at the beginning of last winter, so I know it was really bad. The lines never froze during the worst of the really, really terrible winter before last, but we had lots of snow early that stayed.
One notable exception are some extra TB iris pieces that I tossed on top of a mound of yard dirt and gravel in like, early October(?). This spring the entire rhizomes were showing, along with the tops of the roots, and not a one of those hardy little plants died!
