I know for a fact that with Directv every winter your signal gets weaker, the further North you are the bigger the problem....when the sun quit shining on my back deck, I used to check my signal meter and adjust the dish accordingly ....I would assume it is the same for the computer link signal if they are using the same satellite....
If you live in the Southern US States the loss is minor, Northern States and Canada the loss is significant.
(yes, a lot of Canadians do have DTV using US billing addresses)