Your situation sounds like a two server solution for local. So one server for hypervisor/vms and then snapshots and backups go to a separate box like a NAS. As for "house burning down", a solution for that is off-site backups. I'm guessing building a small TrueNAS server and installing it at a friend's house or your parents or whatever and then find a backup solution to sync(syncthing may be an answer here for you?).
I don't care about my homelab much, but I do care about my family photos. For that I follow my own 3-2-1 where:
3 copies of my data
2 copies are local
1 copy is off-site
I have a NAS at my house and another NAS at my parents house. They are both linked with syncthing and I do a one-way backup to the other NAS. Now, my parents are a 10 minutes away by car, so I consider that NAS "local".
And then I backup my NAS to backblaze for my off-site backup.
I run proxmox for my own homelab and another instance for very small services inside my LAN.
Anyway, I have gotten into docker recently and my method so far has been to spin up a LXC container of just a base OS(like Ubuntu or Alpine or whatever) and then install docker and whatever else inside that container and then run my service.
So I have one container per service. Now my problem is how to manage the docker side without having to go into each container individually. I have tried portainer but it's not clicking with me.
I've actually been trying to find a solution to just have docker on a bare metal OS install and that be my hypervisor, but I can't get a clear answer on anything, so Proxmox seems to be my only option.
Proxmox is a very solid option, but it is not "less intensive" than Debian since it is built on top of Debian. Proxmox does not install a desktop environment(it has a web GUI), so that may help with keeping resources low, but it isn't some magical solution.
I would recommend trying it 100%, there is a little bit of a learning curve getting to know Proxmox, but it's the best hypervisor I've used for homelab so far.