How to recover from failed upgrade...

Is there a simple way to get a system back to a previous version of proxmox, if the upgrade fails?

Just wonder, because I currently have some issues with upgrading from 8.2.2 to 8.3...

I'm only thinking about the proxmox ve host, not the VM's.

I could run a script that backups the important files (/etc/network/*, /etc/pve/*, other?), reinstall from scratch with the 8.2.2 media, copy back the files, reboot. Correct?

If yes, does that backup script exist yet?

Thanks
Dan