Historically when I've gone just before Presidents Day, the resort rates start going up the Thursday before. When I was there the first half of the week before Pres Day, crowds were not bad. And from what I've read here, it sounds like the schools that have a Winter Break week then have the week that starts with Presidents Day. Just my impressions.
ETA the PP is right, you're going to have Mardi Gras crowds the week before PD next year.