I second what the other poster said. The crowds are great--practically nonexistent. But you'll need to be prepared for any kind of weather. The key is to pack things to layer. We found it to be cold in the morning, warms up nicely for the afternoon and then cold again at night. We all brought fleece jackets that worked out well (t-shirt, sweatshirt, fleece jacket--then we could just peel things off).
Have a great time!