Do not try this at home
Put film in a wax in open field leave for over 100 years then developed. I read this one in the paper a few years ago with the photo.

I have use the cold storage and no cold both work for black and white when does it expire if ever may was just good luck The oldest I have use was over 20 years and not store right.
The safe way is use the freezer in a box in a black bag.

Dave