1970s film people frozen to death in car - blizzard

I am looking for a film I saw on TV in the 1970s. In it, some people were lost/stranded in a remote area in a blizzard - desperately trying to make their way through the snow. At one point they find a car, and when they rub the frost off the window they see frozen people inside. One of them cries out something like, "Oh, no, it's the professor!" At another point in the film they find a cabin where there is some canned foot, but they cannot open it because they don't have a can opener (causing some minor panic). It was a film in color, and had to be broadcast before 1979, not sure if it was made for TV or a theater film that was played on TV. Any leads helpful and appreciated!