Yeah, I have an offline backup I do every year in a fireproof safe in my basement. Might open a safe deposit box at some point, but I feel reasonably safe.
Good call on power efficiency. I'll have to keep that in mind. I think I'm currently drawing around 100W which is mostly the hard drives (the CPU doesn't even need a fan). I assume that might go up a bit in a new build, but I think the benefits will be worth it.