The concept of a fortified residence or property is great, but you need people to defend it. Those with an abundance of basic goods may simply be preyed upon.
Who usually wins in this world? The rich of course. Somebody is going to become the "bank" and that person will win. It will take a while for things to settle down, but they will settle down and the bank will win. Hence gold, silver and similar commodities are very valuable.
All that said, you still need to eat and in this world you'll need fuel or a way to make it.
Diversity is the key. There is short term (<6 months), middle term (a growing season or two), and long term objectives (years). Most focus on the short term as that is all that is possible for them. I'm one of them.