Understood, you are right. It does need to be an organized effort. Even with a contingency plan I suppose it's extremely difficult to move that many people and supplies.
People seem to think that the NG is an "on-duty" force that is available for immediate mobilization but that is not the case. The vast majority must be called up from their everyday lives and activated. Given the scope of this disaster one can safely assume that hundreds or even thousands are among those that evacuated the region along with everyone else.