> I do not believe the latent image would remain for 100 years. Then again maybe the cold does keep them.
Four years ago, a friend found a box of color 8mm movie film in his attic. They were 40 years old and never developed. His son begged him to develop them and he finally got them developed. 1/3 of them were worthless. The other 2/3s were as if they had only been taken the day before. They were perfect.
There is a way to special process film which has been exposed for a very long time. Of course it is much more difficult than just running it through the processing machine.