I'm personally a fan of rain pants over winter bib tights when it gets cold enough that tights alone no longer do the job. Cycling-specific pants are easier to ride in (and more aerodynamic, if you want to go fast and turn up the wind chill even more!), and waterproof/breathable ones are better for preventing sweaty legs.
That said, I used some cheaper not breathable rain pants (Helly Hansen Voss, to be specific) for a few years. They will trap the heat and cut the wind, if that's what you're after. Tested and approved on the Wisconsin/Minnesota border.
A benefit of rain pants is that they also work for, well, rain, as well as those spring days when getting covered in sludge is unavoidable.