FWIW, Jeff, it seems to me that your worst-case scenario would be a bad spill with injuries. Broken arm or hand, dislocated shoulder, badly scraped up leg. Maybe a mild concussion, even while wearing a good helmet.

Since you'd be on your own for at least 8 hours, possibly with very limited mobility, that would become a genuine survival situation.

Correct me if I'm wrong, but I get the impression that your gear list assumes you will be generally able-bodied.

Perhaps you should consider what you'd need if the worst happened? If you were hurt, groggy, could only crawl, what would you need?

(Hope this never happens, but it doesn't hurt to think it through.)