You CANNOT get ANY Network programming if you leave the "spot beam" that encompasses your local broadcast area unless you call Dish and give them the new address (service address only, do not change the billing address). That spot beam can be 200 to 400 or more miles wide but once you are outside you will get exactly nothing.
When you are setup for 1 satellite, you will be able to watch any programming you like on the main receiver but the 2nd receiver will only receive programming that is being broadcast from the satellites selected by the main receiver.
If you select the 2 receiver option then you can only lock onto the 72.7 satellite which does not have much of a signal in the West but should be OK if you are East of New Mexico. The good news about 72.7 is that both receivers can watch any channel without restriction. The bad news is that NO NETWORK programming is available on 72.7.