They had a basement with "lockers" which held each member's store of food, ammo, gear, etc. They must have been large considering the number of members and the size of a few years' supplies. It's a good book - heavy on details, and represents a pretty serious breakdown of society. I hope it doesn't become that bad. It emphasizes that there is strength in numbers. If you want to prepare for the worst case scenario, find some other Texans who feel that way too and prepare together. I also envision roaving gangs going through the countryside, killing, stealing, pillaging. If they come knocking at your door, it will be best if there is a group of people to answer their knock.
IEFPRO, if you need to escape Austin, you might consider the Hill Country. Perhaps the Medina/Bandera area. From Dallas, you might consider East Texas or SW Arkansas. It is reccommended you be at least a tank of gas away from urban areas. Keep your tank full. I believe you will know the signals of when to get out of Dodge, or Dallas, Austin, Ft Worth, San Antonio...