I played 18 today on a hilly course where the cart path is often a fair distance to the fairway (it was cart path only). We figured we walked 4 miles with often a good climb back to the cart. I'm bushed. It's a beautiful course but I think I'll pass if it's cart path only the next time I play there.
IIRC they had a Nike Tour event there once. Brett Hull (in his prime) played and he had a difficult time walking this course.