Cold Storage Backup & Config Backup

Upon reading this post regarding backing up your Firewalla's config and settings for cold storage, the response provided was for a box that is still syncing to the app and playing nicely. My question is, what if it isn't?

What options are present for backing up all your Firewalla's settings and config for cold storage in the event that the box is completely damaged and unsalvageable, with the goal to get a spare backup box up and running with zero/minimal downtime? I know that the app also stores all of this information, but what if that also isn't an option?

Just for an example... 

Box A is the primary box with all VLANs, VPNs, rules, groups/users, device IP reservations, networks, etc configured and in use. Box B is a spare in-case-emergency box sitting in a drawer. One unfortunate day, we have some guests over and an unsupervised child sneaks into my server room and proceeds to dump apple juice all over my Firewalla Gold SE. Box A short circuits and suddenly my entire network is offline. My phone is sitting on the kitchen counter and my cat decides this is the perfect time to paw it off the counter, thus falling at the exact angle to shatter the screen and render it useless.

How can I get Box B plugged in and working exactly like Box A was? Given both the box and my phone are broken, how can I restore a backup stored on my computer onto Box B? I'm sorry for the whimsical scenario, I'm just trying to portray a situation where the perfect storm occurs and suddenly everything is in despair.