Ultrium media has a lifetime of 30 years after the first write to the cartridge, and that’s assuming you write to it up to the maximum number of full writes (260).

Assuming you write to your cartridges once, store them (and the drive) in an airtight dustproof box, and don’t expose them to extreme temperature or humidity, you’re pretty much guaranteed to have complete data integrity after the 30 year mark.

At that point, you can probably transfer all the data into your petascale holographic storage installed at the base of your skull.