My university changed their schedule a bit and we had the first two weeks of March off for spring break. We were at OKW from March 4th to the 9th. Crowds were extremely light but since we were staying over the weekend, we avoided the Magic Kingdom on Saturday, Sunday, and Monday. This paid off.
The only time we needed to use FastPass was for Peter Pans flight. It had a (stated) wait time of over two hours. We walked on every other attraction or waited for 10 minutes or less. The weather was perfect, a far cry from the snow we were having at home.