Mega-city? It's a city of 20,000 people in a very small area (1 mile square?). 20,000 people is more like a town than a city and certainly not a "mega" city.
“In my crazy mind, two-thirds of Vermont would be wilderness and one-third would be the farms that are occupied, and you’d have 20 million people in Vermont,” he tells the group, slapping the table.