We live in a fairly nice, very new neighborhood on the far northwest fringe of town. The problem with a new neighborhood is that, given recent immigration trends, it is rather diverse (i.e., English is not well-spoken.)
I've had to go out of my way to introduce myself to the people on our street, and while they all make a show of being friendly at a distance, I can tell they are most likely very clueless.
I recommend owning some land out in the country and making periodic visits out there to get to know the neighbors for the reasons cited earlier from Alaska. My family owns a ranch in the hill country and I go out there once every month or two to write and shoot, and I try to meet everyone out there. They know who we are, so if we had to flee the city because of S H'ing the F, we wouldn't be viewed as strangers.
If budget is a concern, start with a few acres in the country with a small travel trailer for sleeping/living it. (Or you could camp, but country folks will probably accept you more if you live in a trailer. Then, you're just poor. Camping out, you're homeless or a city weirdo.)
It depends on what happens. If large numbers of people are fleeing the city en masse, I'd stay put for awhile and let that die down, unless they were fleeing something I truly had to worry about. Then, when they were gone, I'd go, but with wary and watchful eyes.
I generally try to stay ahead of things, though. Ever since 9/11, I've kept my gas tank at least 1/2 full and kept gas money on hand. Takes 1/2 tank to get to the ranch.