just got back from 9 nights of boondocking in Colorado near Leadville, above 10,000 ft. The trip was fantastic, and scenery unimagineable. though we have a 25g with front pop-out, we turtled the family in as it got very chilly at night.
We hit a couple spots going up into the mountains where the 5.4l Yukon was struggling to keep the camper above 45mph, but for the most part we were able to keep up with traffic very easily. we averaged 9.4 mpg excluding the climb from Denver to Leadville where we were closer to 6. Braking was not a problem coming back down. There was a vicious cross wind in Nebraska on the way out that fully tested the dual cam hitch. Thank god we didn't have to deal with that on the way back!
I expected trouble with battery life since we have a simple marine deep cycle battery. We ran jumper cables to the truck & charged it up for an hour or so around supper time each night. That seemed to be enough to keep the heater running so we were happy.
We went through about 60 lbs of propane including a little red campfire on its own tank that we did most of our cooking over using a tripod. The little red campfire also came in handy once the burning ban was implemented our last 2 nights there. The sheriff confirmed that the propane fire is legal under the ban. It doesn't really throw any heat to keep people warm, but makes a nice focal point to look at when you're not mesmerized by the night stars.
The black and grey tanks didn't hold up for the full 9 days. We had to re-hook at one point to go dump - but not that big of a deal and we expected that to happen.
My son caught fresh trout almost every night, plus all the food we packed kept us stuffed. That's probably why we used so much propane - cooking up all that food to power us through all the hiking & kayaking. We were very happy with the Jayco both on the tow out and on the site. this picture is in Leadville at the dump station. The mountains make a heck of a nicer thing to look at than the stinky slinky during the emptying