What situations would cause you to bug out?

[Lightspeed]

If you mean Bugging Out as in living in the open with just the contents of BOBs, our trigger would be the moment we consider the lives of our group to be in real and immediate peril.

Bugging out for us is a last ditch survival tactic. A desperate measure, carrying exceptional high risk. We only consider it when all other options are exhausted.

Examples:

A mob too large to defend against systematically looting houses one after the other in our immediate area. Ours is next in line... so we evacuate.
A bona fide hostile military intent to aggressively take over our house. We're not going to be able to defend against this threat.
Major fire too big to fight. We get out with whatever we can salvage and only return to recover cached gear after its burned out completely.