So, perhaps looking at the downside can additionally illuminate the question.

If you immediately bug-out when a disaster of unclear proportions / unknown or unknowable variables looms, is it fair to assume you will generaly increase chances of survival and can return if and when said disaster ends or is determined to be something suitable for bugging-in?

If such a disaster threatens to be quickly lethal to those who bug-in and you do not immediately bug-out, are your chances for survival better or worse than those who immediately hit the road?