I did the TLH last month on a Wee with TKC's. I encountered everything from dry to cold, gusty winds and driving rain. I didn't have any dirt experience prior to this ride. I'll second what Mark said. You have to give 100% of your attention 100% of the time to reading the road ahead and picking your line, which is constantly changing. After a while, I was able to interpret what the slight colour changes in the road surface were telling me. When you hit a section with one of the demon graders, there's usually a line through that hasn't been churned up. It may be narrow but it's there.
I had a great trip and hope to get back before too much more gets paved.