Mirroring two separated EX2 Ultras

My son and I live a mile from each other. One 2-bay NAS can be stolen/struck by lightning/whatever, but two mirroring each other - only a meteor can hit both.
So, we bought one EX2 Ultra each with the intention of letting one disk back up the local system and the other mirror the remote backup, so that we have one backup of each system on each address.
Any tips or references on how we should set them up would be much appreciated.

Hi Poultoft,

You can follow the steps from below article to create remote backup of My Cloud EX2 Ultra devices: