Gregory's Server
After researching this problem for myself, I settled on two offline storage media:
1) I buy used 1-TB 3.5" hard drives and offline-storage cases.
The 1-TB size is a good match to my needs, cheap to buy (especially used, and used is fine -- for offline use, they'll get little wear).
2) M-Disc optical disks, DVD-M or M-Disc BDR, which are much more durable than dye-based media (will probably outlast the magnetic media of the hard disks).
@polychrome @atomicpoet @anji
I plan to use the 3.5"HDs to store expanded source trees, software/distro, and the complete EXR-stream renders of my output.
The EXRs are "intermediates". Regenerating them is expensive, but it is an automatic process, once the software is running.
I'll use the optical M-Disc media to store source files, PNG streams, video renders, and software archives.
As for the volatility of PeerTube, that's why I'm running my own instance, now.
Hopefully this works. 🤞