If the receiver is setup dual UHF, you can run an infinite amount of remotes off each "TV". The only necessity is to make sure they are addressed to the correct remote address and that range is not an issue.
Do you have the remotes already?
Once you have the receiver setup to receive UHF command on TV1 (TV2 is by default) then just program each additional remote to the proper address after making sure it is in the proper configuration (color keys, remote dependent). Then just hold down the satellite button until the other three mode lights light up, release, enter the address using the number pad, press pound, and the remote should flash three times. Done.