Here's a link to the dates of the Daytona 500 and speed weeks for the next 5 years!!!
http://www.daytonachamber.com/speedweeks/speedweekcalendar.htm
The Daytona 500 is Sun., 2/15 and the next day is President's Day. I've just begun planning for our next trip -- the Sunday after President's Day, 2/22 through 2/27 for Mardi Gras. (FYI...Not all of Louisiana is off for Mardi Gras, mainly southern LA and not all week. Some just for 2 or 3 days.)
Mardi Gras falls 40 days before Easter, so the date changes every year. Two years ago for our last trip to WDW, Mardi Gras was the Tuesday before the Daytona 500 and President's Day. By that Thursday, the park was getting a little more crowded. But overall our longest wait was 30 minutes and that was for Test Track which had only opened a few months before. (Even with Fast Pass!)
Anyway, with two kids waiting in a line in 70 degree weather beats waiting in 90 degree weather anytime!
The only bummer is now that Mardi Gras falls two weeks later this year, we're going during Peak season regarding resort rates. Last time it was value season and right after 9/11 so we got great rates. I'm hoping for more discounts, in the meantime I'll book any room and just change plans once discounts come out!
Any idea when Disney might announce winter discounts???