I have eaten my deer meat and sausage at two years wrapped in butcher paper in the freezer. I even ate some sausage once from 3 years that was wrapped only in butcher paper. Tasted like chit. Now I vacuum pack it.
I wouldn't hesitate to eat anything 3 or 4 years old. It won't hurt you and salmonella and botulism won't grow in the freezer. The only thing to suffer will be the taste.
Hot Rod Hog Cookers Association, Charter Member, President