We (my wife and I) did things a little differently. Our BoB's are in our (respective) vehicles, and when we worked in the city had everything we might need to get home from work (which was quite a long distance).

So, the BoB's had changes of clothes to start with, food, shelter, medical gear, you name it. The plan was we would grab the BoB, and get to some place we could change into appropriate clothes - and then start walking.

We also had a couple of U-store it units (one by her hospital, one by mine) that had enough stuff for us to shelter in place for as long as a month (with an expedient fallout shelter made from stacked bags of concrete), camping stove and fuel, weapons (California legal of course), more clothes, water, communications gear, etc.

One thing we still do is we have a sealed box of ammo in each vehicle that has a reasonable amount of ammo in different calibers. We were at the range in California the day the Rodney King jury came back, and had to drive through the riots. Lots of weapons, but we had shot up all our ammo...we won't make that mistake again! We take that ammo out and shoot it every six months and replace it, since the vibrations from the car can (theoretically) cause the grain structure of the powder to break down, causing higher than safe pressures. So far we've never noticed a problem but why not be safe?