Interesting story, hope all will be fine soon again. For the safe storage, what I did was to dig a casing pipe into the ground between our house and our neighbours. We have 2 utp cables in this, one for them and one for us. Now we have a NAS in their house and vice versa. We both cannot access each other’s NAS, we don’t know the passwords. Now it was quite some digging, but as a result we have a (we think) safe backup of everything. Chances of both houses burning or flooding or whatever are slim.