Remote backup server would be my suggestion.
Configure it with a VPN to talk to your home network and set it up at a trusted friend’s or family’s place.
I do this with a raspberry pi and an external HDD that takes daily/weekly/monthly snapshots, with daily rsync. Works nicely for me.
We have one kid, one one the way, and then it’s time for a Balls Voyage party (or snipped but still equipped, if you prefer).