When Walter White is in New Hampshire, he was not supposed to have phone, internet, or TV connections. Why can't he use these provided he doesn't do something foolish with internet or phone? And how can police find him by using TV?
Its not that Walter cannot use TV, its that he cannot do anything that is likely to bring him into contact with someone else.
While his name is plastered on television and in newspapers, while the story is fresh in people's minds, he has to stay under deep cover. The 'vacuum repair guy' has one mission, to get Walter started in a new life. To do this he needs to weather the initial storm of publicity.
He provides him with a remote location, unlikely to be disturbed by anyone, food, entertainment - books and DVDs, and warmth in the form of a wood pile and stove. He even brings chemotherapy drugs and learns how to administer them (from YouTube).
He wants to stop any visitors, which means anyone likely to service a telephone, an internet connection, cable service, gas lines etc. He also needs to prevent Walter from contacting his family - no phone or internet, and a long cold walk to the local town.
The cabin seems to have electricity, but this is provided by a generator with a months supply of fuel, as described by the vacuum repair guy.