To re-iterate my other comment, there are M-disc bluray discs now (up to 100GB per disc), which seem to last for 1000 years, if kept away from direct light and

To re-iterate my other comment, there are M-disc bluray discs now (up to 100GB per disc), which seem to last for 1000 years, if kept away from direct light and in good room conditions (low temperature and humidity).