I will be moving into a new house next month and plan on getting Directv. Right now I only have 1 tv. We will be getting at least 2 more over the year or so but right now at install time will be just one. Is there anything I need to do to make sure that I don't have issues when we get those other tvs? Besides obviously getting a box for the new ones when we buy them. How many tv's does a normal install support if you tell them just one with the genie dvr?