As with everything else it is a matter of PREparedness. If you look forward to the possibility that you may be submerged in a lake within your car then you plan ahead and carry a spring-loaded center-punch to break your windows. If you look forward to the possibility of needing the evacuate your home area for an extended period of time you will arrange a destination ahead of time and make friends / alliances with local, stock it with supplies and prepare it for occupancy. That may be as simple as sticking a 5 gallon bucket in the coat closet at Grandma's or it may be as complex as setting up a homestead complete with self sufficient garden and livestock. The level of complexity is determined by the scenarios you wish to prepare for. OTOH, if you have no prepared destination but you have a decent SUV and a tent in the BOB then you could get quite a ways off the beaten path into the wilderness and make a decent stand there. There are a lot of people - true but there is also a really big world here. If you let the population of manhattan loose in an evacuation scenario you will find most of them in other big cities. A small portion would be in the adirondacks in campsites, hotels, vacation homes etc, and an even smaller portion will be in the trackless places of the Adirondacks that may be accessible by driving along a rail-bed for some miles and turning off into the woods / swamps and going even further. Following such a proceedure you could get your SUV off the track and out of site, then pack in from there whatever you can carry on your back and probably make a couple of trips without worrying about having the SUV found. Then cover the trail from the SUV to your Bivouac and camo the SUV in place. This sort of plan when combined with well located geo-caching (perhaps the 5 gallon buckets or ammo-cans or whatever) could provide a secluded remote bivouac with supplies for a year. If the location is well chosen it could be secluded enough to avoid being stumbled upon by others. There was that guy that eluded police for a few years in a mountain-top hideout in PA I believe.