When I had a single cab truck with a topper the Collies would ride in the back. I drove of a night for cooler temperature for them. I would pull into a campground before noon set up the camper have lunch and hit the pool. In the hottest part of the day I would sleep while the A/C hummed away. I would get up eat supper, load up and hit the road. I found it a very enjoyable way to travel. I had cool temperature, less traffic, no wind and always was able to get a spot in high demand areas.
With the crew cab the Collies have A/C so heat is not a problem.