satellite recievers

You can always add an RF modulator to the 211Z to provide a coax output should that be necessary.

Not wanting to confuse the issue further but if you go with the 211z, which I believe is the only 211 that Dish offers now, the only outputs are HDMI and RCA. There is not a RF output if you want to connect a second TV that way. Another reason to just take the Hopper with you. If you only need one TV then the 211z will work.

Another option would be a Dish for my RV account that you can shut off when not using it. Depending on how much you use it, the 211 option might be less expensive as a add to your existing account.

Why not just get a dish and a tripod and take your hopper with you? Setting up a Hopper isn't any more difficult than setting up a 211Z. And as a bonus you can take a joey with you and watch different channels on two TVs.

If you are planning on adding it to your home account, they told me that they will only allow a 211 receiver to be added to a Hopper account.

You can move your Hopper to your RV but you will need a standard Dish antenna like the one mounted on your house (or an automatic roof mounted unit like the Winegard Trav'ler) for it to work properly.
If you would like a separate receiver for the RV, the only receiver that Dish is currently allowing Hopper owners to add to their existing account is the 211K or 211Z (and possibly a 411 since it's the same thing with no Ethernet connection). You would then be able to leave it in the RV, only activate it when you need it, only pay the $7/month additional receiver fee and then only when it's activated.