What always concerns me about those plans is for those that live where the unwashed millions in urban areas plan to "bug out" to... I live rural, so most scenarios would have me "bugging in"... and I have to include plans to deal with the possible situation that someone decides my spread is what they need. My place in Penrose was very defensible (house on a hill, 360 degree views of approach, etc), but was not easily self-sustainable.
Here in Canton, I'll have to get creative with defense (and I have some of de fence work, too), but it's much more self sustainable... greenhouse, garden, chickens, cattle... that in itself will make us a target
Natural disasters are a possible exception (i.e. Harvey)