I'm just north of the Mohawk, which is a somewhat-effective impediment, but the Horde will be here, too.
One thing not mentioned is disease that spreads after a natural or man made event. Hatti is a good example of what people face when the SHTF, diseases come out of the wood work, stuff we only read about in history books.
IIRC, Martha Washington was in Chicago or perhaps Philadelphia when Colera hit, body's were dragged into the street to be picked up in carts for mass burial. She and her servants spent a couple months holed up in a private home away from the people watching the horror from their windows. She and servants finally made their escape back to VA. Some old diary's recount the time as a "uncomfortable" time for her. Poor Martha, all those party's canceled, shopping excursions not to be, is it any wonder she became a bit strange in later years.
Same can happen today and seemed to becoming a fact in the OWS camps, just a hair breath from Typhoid and TB.
All these unvacinated people coming here and we in fact do not really how long our vacinations will last., 10,15years or so.
I worry less about the Bomb or full on attack to us , we can combat that, it is the Insane Scientists that of late developed a virus that is so potent it can wipe out the world. Just how long the secret of the recipe can be kept from others is a question. Science may just be the thing to destroy us.