I don't know if we could handle the logistics of such a disaster or not. I am not well-versed in the capacities of FEMA/Red Cross/National Guard/etc. and what percentages of them are in NO right now, so I can't get a good feel for whether or not we could tough it out. I do, however, have a feeling that widespread panic/chaos accross the entire country would not be as bad as one might think:
Right now, NO is the only real disaster the nation has to focus on. Because of that, all the news media/people's attention in general is focused on it 24/7, and this creates a sense of a huge mega-disaster (not saying it isn't a disaster, of course). If we have 6 or 8 similar-sized disasters at the same time, each one gets that much less attention and therefore seems that much less of a disaster (when it is in fact very bad). 6 or 8 disasters combined then seems only about two or three times as big a disaster as NO or 9/11, when in fact it is 6 or 8 times worse. That is why I don't think universal chaos accross both affected and unaffected portions of the country would be our undoing, IF the government/society in general had the means to supply the populace for it's basic needs.