Greetings!

First: There are many internet articles that are commenting and documenting the problems with our national power grid. I identified "loss of power" as the Number 1 threat that I faced when I lived on Staten Island, And I worked on Governors Island while my DW worked on the 17th floor of the World Trade Center/North Tower. Power supplies are said to become a distinct problem during the summer of 2009 ranging from brownouts to blackouts in many parts of this country. NYC and the Northeast US does not have a good track record in this category.

Second:
I agree about the folding bicycles that have already been mentioned. You can cross the East River via the Brooklyn Bridge.

I also agree that a truck would be more useful across the entire spectrum than a small car would be.

One friend of mine used to carry a heavy wooden walking cane topped with a large brass knob when we'd go to certain parts of the city. I always had my Buck 110 on my belt (early 1980's). It might be a good idea to keep such a walking cane at your office.

Third:
I would think that the best Bug Out route would be via the Varrazano Narrows Bridge to Staten Island and then across the Arthur Kill to NJ. That would run you through the least populated areas of the Megalopolis and get you into the countryside in the least amount of distance. A route that is definitely worth looking at. Otherwise I would look at getting through Brooklyn and Queens to the Throggs Neck Bridge and then you can head in 1 of many directions.

If you know of someone, or if you already own a large enough boat, I'd definitely include that as another Bug-Out option!!

Fourth:
Water has traditionally been the biggest of many weaknesses associated with possible complications involving the loss of electricity in the Big Apple. You might want to keep up to 2 weeks of water on hand at all times.

Blast's "Home Emergency Plan Binder" is definitely worth developing for your Au Pair to check for emergency plans that include instructions for her to follow.

Fifth:
On the subject of "friends" (a very dangerous word), I would sound out those work acquaintances that live near you that also commute to Manhattan. You might eventually find a few that would be interested in banding together in time of an emergency in Manhattan to work y'all's way home from work, as a team. There is some safety in numbers as long as the numbers are not too high.

Just some of my thoughts!