I would think the key to living in the city is that while it will be good to have supplies in place, it might also be smart in terms of getting in place (whether bugging-in or bugging-out) prior to the mass freak-out. In terms of a grid shutdown, you might have a day or two before the city goes into chaos...although I would assume mass confusion would happen relatively fast. I just assume most people will just wait for the power to turn on...The city is a death trap, waiting to be sprung. Get some supplies for your apartment, be prepared to hunker down until you can escape. Our idiotic congressional members only care for themselves, and the fact they haven't protected our grid shows they don't care for America. It's not IF the economy will experience a total Venezuelan collapse, but when.
The scarier aspect will in part be a economy crash...because it may not happen overnight if you will, but a slow drain across the board that will simply start swallowing everything it touches turning like quicksand. I assume most people won't know they are in over their heads until there is no where to go.