You are right. Any N&IO (New & Improved Orleans) is to be built somewhere else - in a different location, with different terrain, and most emphatically with DIFFERENT POPULATION and different political culture. I would suggest German/Amish Areas of PA/OH.
The "different population" aspect is down pat. A lot of the citizenry will not be coming back, no matter what. And with the demographic shift, the politics will change as well.
I, for one, will not return unless that levy system is able to withstand a nuclear blast.