I was at WDW in 2013 on a similar week when Mardi Gras fell the week before Presidents Day. Lots and lots of folks there from Louisiana and the Gulf Coast, but I didn't think the crowds were horrible, and the people were pleasant and having fun. Now it wasn't Super Bowl Sunday that week, so I really don't know what difference that will make - but I wouldn't be afraid to go back for Mardi Gras when it's that early (not coinciding with Pres Day week or later Spring Breaks). Two fond memories from that trip: There was a big, multi-generational family from Louisiana (all had matching yellow shirts) waiting outside MK on Mardi Gras morning. There was also a Mom, Dad & toddler Girl there (unrelated) - Dad was holding the little girl while Mom was eating a muffin, and the Pater Familias of the LA clan, observing the little girl, chuckled and said in this great Cajun accent, "She got her eye on dat moo-fin!" My other Mardi Gras crowd memory was of the young Southern gentleman, 14 or 15, who insisted on giving me his seat on the bus. (Not that there aren't polite young men from all over.)