I have DISH Network at home. Most of their home receivers are designed to be connected to a phone line. However, their single receiver without DVR, their most basic model, is not required to be connected to a phone line. The extra cost for that receiver is $5 per month. Once the receiver is activated by the DISH Network installer (something that can be done on your home dish antenna), you can take that receiver with you anywhere. That's the one I have installed in my RV.
I do not have a rooftop satellite antenna. Besides the expense, my experience is that 90% of the camgrounds we prefer are wooded, and we could not get reception from a rooftop dish antenna. Instead, the fellow we had come to do the installation at home had an extra DISH PRO antenna that he sold me for $50 (I suspect it went right into his pocket). I bought a tripod ground stand for a satellite antenna at an RV store. The one I bought folds up for storage, but the trade-off is that it is a bit unstable and must be tethered to a stake in the ground to avoid blowing over. I also carry about 200' of the high quality coax recommended for satellite signals, I forget the number but it's available at Radio Shack and other retailers.
I don't have much space in my RV, so I have to removed the LNB boom from the dish iteself in order to fit the antenna into the available storage. This is only four bolts and takes just a minute or two.
It takes 10 to 15 minutes to set it all up. This includes finding a place where the antenna can "see" the satellite, leveling the tripond and staking it down, looking up the coordinates for the antenna according to the local zip code, rough-setting the compass direction, azimuth and scew, and fine tuning the antenna for the best signal. The latter can be done by setting the volume really high and listening to the signal if it's close enough, or I bought an inexpensive signal meter that attaches to the coax near the antenna and gives off a visual and audible signal when the antenna is on target.
It only takes a couple of minutes to break it down for storage. Still, the procedure is long enough that it's not something I do for casual stops or quick overnighters. In those cases, I'll just crank up the regular antenna and see what I can get. Also, if I'm in a campground and they have cable TV, I'll usually opt for that instead of going to the trouble of hooking up the dish. If you are willing to spend the $$$ for a rooftop dome (around $2,100 installed) and if you are willing to search out campsites which are unobstructed by trees, the automatic set-up dome units are really nice. For a few more $$$ you can get one that will play while you are moving. I'm not sure that's worth the money unless you are driving during the "big game" you don't want to miss.
I did have to do a little experimenting to figure out the best way to patch in the satellite antenna and still have full access to the rooftop TV antenna (which has a booster installed in the RV) and the cable hookup (which was pre-installed by the RV manufacturer). What finally worked for me was a simple splitter in the right location; however I have to turn the satellite receiver off to get the best reception from the antenna or cable.
By the way, if you get a dedicated receiver for the RV like I did, be aware that it might be possible for it to "lose" the activation if you let it sit too long without using it. The longest I've gone without using it is about 30 days and it came back on, but the installer said it could go away in as little as two weeks. He said you would then have to call the DISH tech folks and get it reactivated. I haven't had to do that, yet, and I don't even know if he was correct or not in his warning.
I've been using this system regularly for about a year, and I love it. No matter where we are in the country, we can watch our local home news broadcasts.