There's a misconception here, I think. "Backups" are the problem, not the solution. Once any one of them is compromised, the money is gone. Having more backups increases your risk.

I don't play in this world, but if I did, I'd note that the actual keys required to define a wallet are trivially small and comparatively easily re-entered at a keyboard by hand. If you're got millions in this stuff that you need to park, delete it from the internet, print it out, and stick it in a safe.