In some locales, fewer mouths. MANY fewer mouths.
In other areas, they'll have The Golden Horde
I think that people are being naive about what would happen to agriculture and ranching in an event like we seem to be talking about here.
With no transportation for the farmers and consumers either one, what would happen?
Modern agriculture is more similar to industrial production that depends on electricity, water from the government, pesticides and on time delivery of seeds and materials, gasoline powered equipment, technology, canning plants, and the staples moving vast distances to markets.
I don’t see our wheat and sugar, and eggs, and rice, and cooking oil merely shifting from Safeway store shelves, to being sold in the Safeway parking lot in a Farmer’s market.