The rules are pretty interesting on the 400, for team or solo. You can't leave valdez without a pace/support vehicle, and between 12 and 5 am your pace vehicle must drive behind the rider and keep them within the beam of the headlights at all time. If riders pass one another their pace vehicles have to make the pass as well, which seems kind of awkward.

I don't know how the switching of riders would work, I personally would want to do a lot more than 5 miles at a time, but that tactic probably works pretty good if you're doing the time trial race. I'd probably just ride to be out there riding. Otherwise maybe every 25 miles or so would be a nice switch, that's about 1 to 1.5 hours of riding depending on terrain.