I've done a similar ride
(
http://bayarearidersforum.com/forums/showpost.php?p=6712012&postcount=1 ) , and I thought I'd share what we did on that ride.
On the highway, we had no trouble keeping each other within view.
In the mountains we'd ride our own rides and sometimes hang together (but not a requirement). We can pass each other and stop (for photos, restroom) anytime without disturbing other riders. We were pretty experienced riders though; a new rider may not feel comfortable riding like this.
These mountain roads are almost perfect for spread-out sort of riding becaue there is no way to get lost. Plus, it gives each rider individual decision on whether to pass cars or cross the DY. (E.g. I cannot pass cars easily because of my MC's lack of hp + I'm too heavy).
In the end, the time delta between first-to-arrive and last was maybe 10mins tops.