I was in the NYC blackout in 2003. Staying at the office overnight wasn't so bad, since I was prepared with food, crank radio etc.

If you HAVE to get home and have done your homework, you will know where the public shelters (usually schools, YMCAs etc.) are located. Break the 21 mile trip into short trips from shelter to shelter where you can rest, warm up and get a bite of grub.

If know NYC has a great emergency preparedness website that shows where the hurricane impact zones, escape routs, emergency shelters are. Anyone in a large urban area would be wise to make a copy of your city's info and put it in your BOB.