We carry a dish satellite antenna and I would not recommend mounting it on the roof. You need about 50' of coax (for satellite) and then just set it on level ground. You will find that where you park or camp will almost always have trees that will block the signal. You need to move it around to get clear skies to the south.
I would buy the carry case that they have and not mount it on the roof. You will always need to move it.
"At some point, throwing money at the problem *is* the right answer", Uncle Bob
Tom & Doty
2019 Airstream Classic 30 Twin