I know that making networks out of duct tape and bubblegum is a point of pride in the Linux community, but if you have to store vital data, wouldn't a nice hardware NAS and a RAID array be a better solution?
My brain didn't even register that the meme was about NAS data residing on the SD card. I automatically assumed it's on attached disks and was about to snark-reply about keeping a cloned SD card taped to the Pi case for such occasions.
I've grandfathered an unlimited account at an independent company with no storage or speed cap with physical storage in a country highly rated for privacy. Even considering Amazon/MS as a potential hosting provider is... Something I wouldn't do.
Funny. My WD nas runs linux and the support ended so i've had to upgrade myself with entware... and it's old, so the fan was sized for cooler hard drives, so I cut a hole in the top and screwed on another fan... and WD removed NFS support years ago, so I just mount my shares oversshfs... and i'm currently upping my local security so it's only accessible over wireguard... honestly, I have no idea what it's doing with the hardware raid and the way it mounts drives so i'm tempted to switch over to mergerfs and snapraid...
Basically my legit consumer hardware raid nas is more duct tape and bubblegum than my home built linux nas. Then again, it's easily a decade past its anticipated useful life too.