As fun as it is to plan for a longer-term bug out situation, I would probably be like the majority of folks here and just bug in. Beyond that would be traveling to another local area to stay with relatives or friends and pool resources.

My realistic concerns are something along the lines of a hazmat incident (trail derailment, fuel tanker truck explosion, etc.), low level flooding, the possibility of earthquakes, and a wildfire sweeping through the rural areas, severe winter storm, etc.

All-out nuclear war or a large scale terrorist attack are something to daydream about, but aren't very likely in my area. Not saying that it can't happen, but accidents and natural disasters are much more likely.

So there's a range of time involved:

Hazmat incident = Prefer to shelter in place. If not an option; go NOW, uphill, upwind, upstream. Grab your BOB and head out.

Natural disaster = Same thing, shelter in place. If evacuation makes more sense grab your BOB, some additional supplies, and head out.

Terrorism or WW III = Most likely the same response as above, but with more emphasis on personal safety and protection.