Famine is a big deal. I think that it will take less than a year for society to restore order. At 2400 calories per person per day, one year’s worth of caloric intake is 3,500,000 calories for a family of four.
One example of one year’s worth of food would be:
40 gallons of vegetable oil (1,200,000 calories); and
29, 50# sacks of rice (2,300,000 calories)
An ongoing supply of 3,500,000 calories per year is provided by 12,000 s.f. of potatoes.