I have found this varies quite a bit. In many public campgrounds, and private RV parks where you choose a site to fit your motorhome, a trailer will end up in overflow parking within or outside the campground. This works the same for flat-towed vehicles, boat trailers, or accompanied separately driven vehicles and their tows. However, for big-rig sites in big-rig friendly RV parks, it should make no difference whether you trailer or flat-tow, so long as your rig fits on the 60-80 foot site.
Tom Test
Itasca Spirit 29B