In our case we bring a second receiver if we plan to view on more than one tv. We did purchase the same Directv HD sat dish we have at home on Ebay and mounted it on a portable stand. There are automated roof-mounted dishes that are capable of delivering Directv HD content, but we didn't want to spend the nearly $2K for the installed system.
We have been setting up the standard definition Directv round sat dish for many years anyway and found setting up the HD sat dish to be just as easy, plus we camp among the trees often and need to be able to move our sat dish around to get a signal through the tree cover. We carry 150' of coax although 50' usually is sufficient.
We use bedroom HD receivers and since we use the same dish we have at home, pointing the dish is really all we have to do as there is no need to go through set-up routine on receiver. Obtaining a signal is not difficult once you master the routine, but if you have little experience there are some devices available at Camping World that can help. There are some videos on-line that can get you acquainted with some of the parameters involved.
We never travel without our satellite dish as we can set it up usually in 10 minutes, less sometimes if there is open sky to the south and ground is level. Even when RV park provides cable or OTA is readily accessible, we still set-up satellite as nothing compares to what sat tv can provide. We have the routine down to an art and easily enjoy every channel we have at home, including locals if within NM, with very little effort or issue.