No expert here, in fact Jerry will probably end up having the best knowledge with this...
But you will probably need a lot, depending on how long you plan on bugging in. Think about how much food you normally eat and try to compare. Plus, you should order a few cans and make a test run seeing how long they last and how well they store, etc.
I keep some food like that for absolute emergency, but the best bet is probably overstocking regular types of foods that have long shelf lives and rotating them out as you buy more, using the oldest first. That food is cheaper and many canned foods have long shelf lives. Plus Jerry teaches a canning class that I would love to get to some day.