Australia is an ISLAND - a big island, but an island nonetheless. And yet people GOT OUT.
I would not care if I had to drive all the way from Houston to Fargo, ND. If that is what it took to get my family to safety, I would do it.
The problem with evacuating NOLA was that everyone waited until the last damn minute - had people left from the get go, a large part of the problem would have been averted. Houston is three times or more the size of NOLA, but you can bet your bippy that as soon as they started talking hurricane Rita, we were in the car and headed north, along wth more than three MILLION of our closest friends. Yeah, it sucked, and yeah, I had a nearly 2 year old kid in the car for 15 hours, and yeah, it took forever to get to Dallas, where we stayed with friends, and I know people who went all the way to OK. But we got out. Fortunately, Rita was a fizzle, and that's fine, but rather go early and look a bit foolish if it is a waste, than wait too late and die.
So you can't tell me there is no way to evacuate NOLA and its less than one million population when Houston, Galveston and FIVE SURROUNDING COUNTIES with a total population of more than 5 million did it for Rita and Ike.
It is a matter of effort and taking responsibility for your own.