Hi Walter,
I haven't been to OKW, specifically, in this time period, but I have stayed onsite in this timeframe. I can tell you we found it to be not very crowded at all. The weather was very different the two years I went. In 2000, we had sun and 75-82 for the entire week we were there. But in 2001, it was much different. It was rainy and 48-55. I'd say you really have to keep close watch on the weather forecast the days before you leave and pack shorts & jeans along with a light jacket or sweatshirt.