Script created to self destruct the install in the event of no user input after 24 hours. That should resolve that dilemma 
I guess a month here, but my setup has no dumb fallback. If HA is down everything is down with the exception of a very few devices and lights. I do think my setup is mature enough to run it uninterrupted for months without maintenance.
Having a dumb fallback also meant less advanced features on my wall switches (which are all hue) but with HA I can use these switches to switch on my vacuum or wifi devices/lights (remember hue is zigbee and can’t communicate with e.g. a sonoff).
In addition I also moved all automations to node-red so that none of my automations would face breaking HA changes like it happened in the past nor does a HA restart reset timers, delays or timed conditions, since they’ll continue to run. (E.g. you have an automation with a wait for, or a delay. If you restart HA, these automations will need to trigger again).
At this moment I only ever touch HA if I see something cool to try or to update. It has been running like this for almost a year now without major problems or outages.
Though admittedly, if I would die (and the server) the house will be virtually unusable unless everything is reinstalled the way it was (or simply turning on the server would probably just work until any of the components die)