I suggest you sign up. Since it's lottery no telling if you'll get in or not.
Some of my friends have gone and not completed all passes. They say the ride is hugely fun because all the locals come out and support the riders. The area isn't very populated so having the community support is pretty neat!
Also,if you do get in, you'll have a chance to find out if you want to do the whole ride the next time if you don't finish. I know of people who start earlier than the published start so they can at least try to finish by the cutoff times.
Go for it!