Do whatever you're comfortable with, I have a set of BT45s that are 10 years old now, never been run, inflated and on bike, no cracks and stored in a heated garage and they are still soft. I wouldn't even consider not using them, I probably wouldn't run them at triple digits for a long period of time. If I were doing a lot of high speed riding I would probably replace them just to make myself feel better.
Everything I've read says it depends on storage and usage. Tire manufacturers usually say between 6-10 years in storage but there are no tests I could find and they even state there are way to many variables. I have 1 bike that has 10 year old tires and they are noticeably harder, it only goes out to cycle the oil and then goes back. If I were going to ride this bike often, the tires would get replaced immediately.