I had similar requirements. I switched to Baikal, which has been happily running in a docker container ever since.

Im using borgmatic, a wrapper around Borg that has some extra functionality.

Very happy with it, does exactly as advertised.

Wireguard-easy is plain old wireguard with with a nice web interface for management, that’s all.

It’s easy to set up and use, I’d recommend it.

You can sync easily to another device on the same network via ssh for example. You can also call a script automatically after the backup has been created and do your custom stuff in there.

I’m really liking borgmatic myself as a wrapper for Borg.

EDIT: I don’t have experience doing full OS backups. I only make backups of specific directories.

My solution for a power efficient setup was to split it up: all the services I use but don't need all the time, like jellyfin for example, I host on my nas. I only turn that on when I need it.

The stuff that's running all the time, like home assistant, addblocker, etc, I run on a raspberry pi.

Might not work for everyone, but I'm happy with it.

I do exactly the same. I do not have a lot of data I feel a need to backup. I have a nightly job that zips and then encrypts my data, then rclones it to off site storage.

I have one 3B running adguard and a wireguard vpn server. Another 4B doing the same, plus kitchenowl and home assistant.