Small towns are the least likely areas to be affected as people are already isolated....Not as much as you assume. Interstates, the motor vehicle, small planes make us ALL vulnerable to this spread. The mail, UPS, FEDEX can also spread this scourge.
Delivery drivers. The elderly couple who take the trip of a lifetime to England to see where his Dad was stationed during the war and where the family comes from. They fly back with a small cold, and before you know it, the whole town is infected.