Yes, best refer to this is a cabin/camper, etc. They you should not have problems. But DON'T connect your box to your sister's house telephone or broadband.

For what it is worth: Dish would have gladly allowed external HDD's to be taken from one account and played back at another Dish account, like your sister's or neighbor's. That is a reasonable example of sharing among private parties content that is not and act of piracy. However, the content providers, mostly the big movie studios, require Dish to make such technology in operable in its external HDD feature. So, now the movie studios have good people like you in the position of having to be a little sly with Dish, or any of the service providers, as they have the same restrictions. Yes, how great DMCR is to our great country. Funny, because you can by a DVD and take that to your sister's and show it. But, if the movie studios could get away with it, they would force implementation of technology that would have your DVD or Blu-ray play on only the player you own, so you can't play it at your sister's and you would have to buy the DVD or Blu-ray again, but that would cause a huge firestorm of backlash. The content providers really do believe that when you purchase their content, you "ethically" only have the right to view it at your home ONLY.