I think you fear "being cut off" because you are thinking one dimensionally. Even if land routes were completely impassable, there is still air, and your interest,sea transport. I still urge you to assemble basic supplies and prepare for a possible short period of self reliance. If you analyse most large disasters, emergency services, while initially overtaxed are quickly bolstered with National Guard, sister state services etc. Facing a disaster is just like getting lost. It is far better to stay put, make use of your preparations and wait for help. Emergency services won't be looking for a small boat in Connecticut if Long Island is in trouble.