I do not know if the HOPPER can power a Tailgater.. I have a VIP211 that I'm not using. (I USE Ota).. but I also use DVR's cause I don't watch TV at 3am and some of the good shows are .. Well, 3am)
However this is Generic: Many RV's do have dedicated "Sat-TV" cables. they may go to the roof to to a connection down below
Rooftop installs suffer from "Signal Eating Tree" syndrome. Not good
Ground mounts can often get around said tree.
RG-6 Cable is specificed for Sat work
Many RV's are wired with less expensive RG-59
Thus I recommend you install your own dedicated cable in most cases.