When we got our new motorhome several years ago, we bought a portable dish as I hated the roof mounted manual dish I would always have to fool with for so long to get a signal on our previous coach. After about 6 months, I ended up climbing on the roof and mounting it permanently (Winnebago had a connection hidden under the skin of the roof and a template for making the hole and finding it). My experience was that while the portable made it easy to get out from under trees, you then had the problem of dodging plants and other obstructions on the ground. It seemed half the time I was placing the dish on the roof anyway. My suggestion to you is a roof mount. One less thing to worry about setting up and breaking camp. Most people with sat are commercial campground users (to have the needed 110 Volts for the receiver and not running the gen) and you will find that they are quite hip to sat users and all you need do is ask for a sat friendly site at checkin and you will be put in a spot with a view of the sat.
