What time are you planning on meeting on the 17th? Have you and your friend rode trail 6 before?
It’s a high of 94 today and was even hotter last week. Definitely recommend a early start. Most of 6 will be ok and there is a fair amount of shade. The rest of FH will be a red silty dust cloud.
Staging at China Wall you take 5 over to 6 which is fun and can be challenging depending on skill level. They have been working on 6 and the level of difficulty has gone down but still has it moments. There are a couple of other places to stage. One being an additional 8 miles or so of high exposure single track. How difficult of a ride are you looking for?