First, you must understand that if you get a Hopper and 1 or more Joey's, only the Hopper is a satellite receiver and only the Hopper is a DVR. The Joey's are complete dead boxes if not connected to a Hopper.
If you want to leave the Hopper behind you will have nothing to take with you.
Dish appears to be trying to work with you to put together a system that would allow you more flexibility but you are either confused or not willing to accept that reality.
Before you move to a dual tuner or other DVR option for your RV you will need to decide what kind of antenna you will be using in your RV unless you have NO INTEREST of receiving satellite TV while you are away from home. If you plan only to watch what you have recorded while away from home then any of the high capacity DVR options will allow you to watch what you previously recorded while in the RV. It's only the Joey's that cannot be used when away from a Hopper. One other thing. You cannot use the the Hopper and Joey's and some other DVR in your home setup so you have to pick one or the other.
Some of these issues go away if you choose DirecTV instead of Dish.