[bombcar]

The best "emergency supplies" are consumed over time, to keep them fresh. If you're planning ahead, you just make sure that the consumables you have that can last a month, you have a month supply of.

And that is expensive (something like $1k per household, perhaps, based on https://www.costco.com/chef's-banquet-one-month-emergency-fo... ).

The US is amazing at transportation in general, and it makes more sense for each state to maintain emergency supplies they can move in a moment's notice.

But households should in general be prepared to survive about a week without outside assistance; if you're more wealthy you can increase that.