> enough ... to intervene over Taiwan

Probably not. My guess is the Pentagon's calculation would be that the cost to intervene would be unacceptable and could not be sustained anyway; many reports say the US would deplete their ammo stocks for such a conflict in like a week, and that was _before_ the blunder in Iran

> Better ... than none?

For sure. But doesn't solve the problem of "how do I survive if the power grid goes down for over a year?" Best solution is to get out of USA prior to that event. I don't think any amount of prep will significantly change your outcome in that scenario if you remain in the US.