I was reading this when I suddenly had an idea. Certainly it is a roleplayers idea with a certain macabre sense of humor - and probably a bad idea at that.
Let's just leave New Orleans there. Evacuate everyone who wants to leave and anything considered valuable enough and then set up a wall around it. Let those who want to roam and rape and pillage stay there and have their life the way they like it.
At least we'd have the first mad max style western city where no law nor anything else of a civilized society existed - a heaven for all would be roleplayers to study and to take ideas from. A source of endless amount of movies and songs and the like. Young rebellous people could travel there with their guns and be tourists in a lawless city.
A dream come true for anarchists and anarchocapitalists alike.