Also you didn't take Kinect in to account. I think people are underestimating the amount of watts Kinect uses if the thing requires a fan to keep it cool.
Kinect2 and the associated processing was supposed to take an additional 20W over the consumption of a console (according to the suggestion to the EU). And it looks like "voice activated" standby for the mics&jaguar is ~14W. It shouldn't require an immense amount of power.