I used to live in Oregon and went to the show maybe half a dozen times. Since I moved back to California, I still try to go back for Sisters. I went last year and am going again this year. I have never encountered heavy traffic, arriving or leaving the show. But that's because I get to Sisters before 8 in the morning. At that time you can park right in town with no problems, the crowd is smaller, and it is cooler. Usually we've seen most of the show by 2 or 3, so we leave before the crowd. (The show doesn't officially start until 9, but most of the quilts are already hung long before then. The worst that can happen if you arrive early is that you have to watch the firemen up on the ladders hanging the last few quilts. I can live with that.
)