On the video it looks to have some pretty decent vents which work much better than cracking windows (vents keeps bugs out). On a moderate night you could get away without idleing.
Our 12L 435 horse Mercedes engines burn about 1 gallon per hour idling and our old 12.7L Detroits burn about .75 gallons per hour idling. A 10 hour break is currently costing us around $30 if the truck idles all night.
So if 1/2 the engine size would get twice the economy idling, it would cost around $15 for a night and use about 5 gallons. Does that sound about right?
If you had a tag along trailer, you would probably be better off buying a used slide in camper. It would have a sink, toilet, small stove, sleeps more than 1, and you can take it off when not in use.