You can't beat Acme or Felix for casual. Across the street from each other and no reservations. Just gauge the line and get in when it doesn't look bad. Both are great. I had a quick pregame meal at the bar at Felix right before making the walk to Superdome last time we were in Sugar Bowl and will probably do the same. Bourbon Street itself will be phenomenal on gameday. It will be packed with fans in town for the game so not the typical scene. Two of my favorite pre-game afternoon drinking days were '03 Final Four and '19 Sugar Bowl. Just a great, unique scene.
As for classier bars, we always stay at the Monteleone (and doing so again) and will spend a lot of time in the Carousel bar there. It's great regardless whether you luck into an actual "seat" on the carousel. Also, take your wife over to Roosevelt Hotel to check out the Christmas decorations (they go way over the top and pretty impressive) and grab a drink at the Sazerac Bar. I bet we try to grab a pre-dinner drink there on NYE.