perhaps as bad as Katrina or Harvey from a few years ago
It has the potential to be worse. Katrina passed to the east of NO, the "good" side. The northeast quadrant of a hurricane is always the worst, stronger winds and more storm surge, in Katrina this all passed east of New Orleans, the result was a ~8 ft storm surge in NO, and ~24 ft to the east in Mississippi. If the storm had tracked 50 or 100 miles to the west things would have been much worse in NO. Ida is currently forecast to follow that more westerly track exactly.
Harvey first struck much farther west in Texas. The tremendous flooding damage it weakened to a tropical storm and slowly drifted eastward. The flooding was mostly from heavy prolonged rain, not storm surge. That's not likely to happen this time, but the storm surge risk is real and significant.
Betsey in 1965 was the last big one, in the NO area, before Katrina. It followed the most westerly track, similar to what is forecast for Ida. It did a lot of damage in NO, however it did not cause as much damage as Katrina. I am not quite sure why, but I do know that in 1965 Louisiana has a lot more coastal marshes and wetlands to protect it. An awful lot of that's gone today. My aunt and uncle and cousins were in Houma for Betsey, the eye passed right over them. Their house survived, the same house my aunt still lives in today. Hope she is so lucky again.
The hospital situation was horrible in NOLA post Katrina. After many days at searing temperatures, flooded lower floors and no hope of evacuation, one doctor (reviewed and not charged due to the circumstances) euthanized several critical care patients that were too ill to move before landfall.
I have a cousin who was a nurse in one of those hospitals. She was lucky not to be in town when it happened. Her description of conditions at Charity Hospital were almost unbelievable. As you say flooded lower floors, no power, no water, no working toilets, stifling heat and stench.... The doctor you mentioned could have left at any time but he stayed to endure those conditions to do what he could for the patients, incredible that he was even investigated. Evacuation of the healthy was not the problem...