My pack will sustain me for three day. But I know i would not want to rely on it for long. On the other hand, My jeep is always ready, with a full tank of gas, 10 extra gallons of gas and 12 gallons of water, and all the heavier supplies and extra food/ammo I won't carry.
In the ultimate scenario my jeep is my BOB. It is packed to support one man for two weeks. I can easily make it out of the city and into the hills, provided I have a fair warning. But when it all goes south, you never really know what you are up against until it's falling in on you, so really I think 100% prep is impossible. Having a plan is as good as your gonna get. Good stuff though, nice to see there are some thinkers out there. I like seeing how others prepare, gives me ideas on stuff I may have overlooked