Direct TV App and Apple HDMI adapter - DirecTV

If you have Direct TV and AT&T unlimited Data you can stream your Direct TV through the App on iphone or ipad without it counting against your Data, correct? Because it is my understanding that at 22 gigs it will be slowed down to the point that the streaming may not work. If you are traveling in an RV with no wifi available can you use an apple HDMI adapter which plugs into your phone or ipad and HDMI plugged into the TV can you then stream through the Direct TV App from your phone or ipad and see it on your TV instead of having to watch on iphone or ipad?

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