I have a proxmox host on a HP Elitedesk G3 with an i5 7500. In that I have a VM with HAOS and it runs like a dream. If something goes horribly wrong I can get remote terminal access from the proxmox interface along with rebooting and backing things up.

Also, you can actually run Grafana under HomeAssistant directly, though that does mean if HA is down then you also lose Grafana at the same time. IMO it is reasonable to use lots of stuff alongside HA but monitoring and remote access should be on a separate machine, and for that I have an old laptop (integrated battery so no need for UPS) and that machine is really only for managing remote access and monitoring.