We tent camped for a few nights but the wind flapping on the tent got kind of annoying. Three people in the group slept in the camper shell for 4-5 nights (it smelled as bad as you think it would). I made a nice little home in the back of my Tundra. We brought stuff to bivy but never ended up doing it.
Pro Tip: Hang a bedsheet over the seats to create a mini tent inside the truck. It boosts the temp significantly. I was sleeping with morning but a woobie by the end with mid-30 lows.