My (steel) Kuwahara Cascade and Shasta both served me well for at least three winters each and were in such nice shape afterwards I retired them from winter duties and turned the Cascade back into a touring bike and the Shasta into my main commuter.

I ride nearly 365 days of the year and our winters are about as harsh as they get and people cannot believe either was a "winter bike".

Frames have been treated with frame saver, got waxed once a year and were just maintained properly... they have little to no rust on them.