Washington
Hopefully this doesn't count as thread necromancy (it's a little less than a month old), but the commentary around the military surviving (and the fact that I've drive I-90 a dozen times or more to visit relatives in the Silver Valley up in Idaho) post-Change I decided to look into Washington State and it seems that Stirling missed the presence of two of the highest wheat producing counties in the United States, Lincoln and Whitman Counties; Lincoln has a population of ~10,000 at change, but has 500,000 acres of wheat planted and can produce close to 25 million bushels a year. And it's ~60 miles from Spokane, which means that those that make it out can be absorbed by the rural populace who will be desperately short of hands to bring in the harvest. Similarly Whitman County produces more wheat, barley, and lentils than any other county in the United States, and is home to Washington State University. With only ~40,000 people, it also seems to be another prime location for post-Change survival.
Yet the books seem to completely miss the fact that most of Eastern Washington is a giant wheat field. Maybe I'm missing some factor, like a heavy dependence on irrigation systems that will shut down post-Change, but still the opportunity was there. Especially if Fairchild AFB rallies and marches south, the primary centers of Lincoln County are two days' march away.
Any thoughts?