I bet there's at least one idiot out their with their bitcoin wallet stored on Google drive, and didn't bother to write down the seed...

Easiest way to add a ton more storage is an HBA card with external SAS ports, and a JBOD disk shelf. A disk shelf is basically just a power supply and a SAS expander card hooked up to a bunch of disk backplanes.

You can find them used for reasonably cheap, or build your own from old parts if you're on a shoe string budget and don't care about hotswap bays or anything.

They will act just like any internally connected hard drive, so you can make them part of whatever RAID or ZFS arrays you want.