Many portable generators have digital circuitry now and would be useless if a high enough field were applied. But I agree, much hysteria exists on the issue.
Meant to add that even if you can start the digital generator it likely won’t be capable of producing AC output. Both of my generators are kept in metal boxes of one kind or another. Not real Faraday cages but maybe a little protection.
Ok, now let's look at how much food they can produce quickly. Let's say someone gets an old John Deere up and running and they plow a single 640 acre field (that is 1 square mile) using 60 gallons of gas. They plant corn and becuase they harvest by hand, they have a poor yeild of 100 bushels per acre (a typical yeild for corn is around 160 to 180 bu/acres).
While the corn is growing, they manage to build a mill that will use either draft animals, a water wheel, or a wind turned stone to grind. So after the harvest, they are able to use this crude mill to grind the corn into cornmeal. At 100bu/acre they would have 64,000 bushels to grind and assuming a low production rate of 10lbs of corn meal per bushel, they would end up with 640,000lbs of corn meal.
That would be 14oz of corn meal for everybody each day for a year. That is the basis of their subsistance diet.
That is a single field using 60 gallons of gas.
Onions, carrots and turnips are all long storage foods. Tomatoes, greenbeans, beets, cucumbers and okra can all be canned. Squash and strawberries would be seasonal, but would add to the diet. And all of the above have short growing seasons and could be gardened.
Peach, apple and plum trees all grow easily in that area to add to the diet.
Yes, many people would die, but with a few days to map out a plan, many small farm towns could find ways to stay going indefinately.