When I had the diesel pickup and trailer I used to scout out the campground area when pulling in that afternoon. Looking for a way to warm up truck without annoying people.
As long as I could drive slowly on the cold engine I didn't feel any need to warm up the engine. But I didn't want to slug the cold engine with a tough freeway grade or high speeds. I'd look for a 25 zone where I could drive around for a few minutes. A parking lot or a remote area of the campground. But I wouldn't subject fellow campers to warm up noise and smell in my campsite.
