I have done that as well a few years back. I was up front about it with DIRECTV and was never told me I couldn't do it... Sometimes my older SAT RCVRS would lose their settings when I unpluged them from 120VAC. So when we get setup again I have to call Directv and have them reset it for me. I have also logged into DIRECTV online and reset it my myself.
The big thing is to have your account info with you and which SAT RCVR location in your house you are talking about...
Worked great for us getting Standard SAT TV in our RV Trailer travels.
When NATIONAL BROADCAST went to digital HDTV signals from the local towns I just stopped bringing along the SAT STUFF...
Roy Ken