It's possible that:
* You might have misremembered the title or year. Could it be a different movie, or a different year?
* The movie might be less well-known. Try searching for the movie using different keywords, like "Polish movie 1968" or "273 days below zero" along with "Polish film."
* It might be a TV show or miniseries. Double-check the medium.
If you can provide more information about the movie (like the director, genre, or plot), I might be able to help you find the cast.