Thanks Web, that hits the issue I was trying to discuss.
I didnt think of the sunlight during the Winter time as an issue, I only thought about the temp as the crucial factor. Greenhouses or cold boxes would be common since finding plasitc/windows/glass in the NYC area isnt going to be a problem, but making enough of them to feed a few thousand people during the middle of winter doesnt sound like an option.
Looks like fish stew and hardtack until the first crops come in. What is the growing season, like when do most people plant food and when does it get harvested?
Side note - I need to start a garden.