As for the person many posts back worried about them not putting the order through without a Joey: Don't worry about this. When I had my Hopper installed 6 months ago they couldn't put the other through without adding at least 1 Joey and just told me to have the installer cancel it off the order when he arrived. He swapped my dish to a 1000.2 with the new LNBs that have the switch built in, installed the "Solo Node" device inside (I prefer to have as little as possible outdoors), and that was that. Worked like a charm.
So what you need to do is call them, get setup on their "protection plan" for $7, then ask them for the number of a local installer and get it scheduled. You can have your multiple hoppers (up to 4) installed inside your house. Problem solved. No self install required. Just make sure when you call the local installer they know how to do the switches properly to feed your 3 hopper properly. Some of the new installers are still confused by the Hopper new LNB and switch setup. Since you have/had 6 total tuners with your two 612's and one 722, for the same price you will now have 9 tuners. Or 12 if you add the over the air tuner to each one.
As Charlesrsehll showed in his awesome setup, anything is possible
As for the rest of this topic about multiple Hoppers on same property:
I just got off the phone with them an hour ago to order a 2nd Hopper with Sling because I want to install it on my shop (aka man cave). Which is on the same property. Since my shop is about 115 feet away from the house dish, and I'm certainly not going to bury coax out there the CSR suggested I just put another dish on the shop itself. Their rule is that you cannot install on a building over 200ft away. I asked if I'd have to buy the 2nd dish and she said no, not if I sign up for the protection plan, then just turn off the protection plan after the install was done. So that saves me $40 plus the install fee which is nice. I also have a 211 on my motor home and that isn't an issue either. I told her I don't have a phone line or internet out there and if the Hopper would still work. I was told the only thing is it won't be able to download PPV/web content over the internet but of course all the normal satellite stuff would work, except no sling capability obviously. But I'm still going to get the unit with Sling just in case I ever run a wireless network bridge out there (I KNOW my WiFi won't reach. I have metal siding on the house and metal shop) I did ask her if it was ok to take my (future) shop Hopper up with me to my cabin for the weekends and she said yes and suggested I buy a tailgater dish.
So that is the latest info I got. Going to get my 2nd HWS ordered this week and mount a second dish on a pole. Looking forward to having my own dish in my "man cave" out of the house.