We go to disney the week before Presidents Day every year. It's LOVELY! Crowds are light until Fri/Sat (and even then I don't really consider the parks crowded). Weather is different from year to year, but usually a few warm days. We don't even make PS's until the weekend. We just wander and do what strikes us. The only thing we still do is hit fantasyland during the early magic hour. If you do EE the week before Pres day you'll have the park almost to yourself. Expecially if it's chilly.
The only drawback is scheduling--they usually don't have spectromagic until the weekend. But I'll trade missing Spectro for Fantasyland to myself anyday!
Jenny