I am making an educated gues that the crowds should not be a problem during your dates. We are planning on a 3/8-3/13 trip. I know that March is considered "peak season", but if you note the MK park hours for early March, it closes no later than 8pm or so until the third week of March. During that week you see closing times stretched until 10pm-11pm or so. Supposedly WDW bases its park hours on expected attendance, so therefore I expect small crowds during the first two weeks of March. But Disnery always reservces the right to adjust their hours, alothoug I've never really seen that happen.
I don't like to think negatively, but this really should be the case. I mean how messed up would it be to pay peak prices, have short hours, AND big crowds?