Force external display into HiDPI mode?

I have a 40" 1080p TV that I use to watch Netflix by plugging it into my 13" retina MBP. Video looks great, but using the OSX UI is difficult as everything is so small from across the room.

I would like to run the external monitor in HiDPI mode so the videos remain high quality, but the UI elements and text are larger. The HiDPI resolutions are not listed in the Display Preferences, even if I hold down the Option key when clicking "Scaled", I have also tried using Quartz Debug to enable the HiDPI mode but it is already enabled, probably because the 13" monitor is a retina display.

Does anyone know a way to force an external 1080p monitor to render OSX with the larger IU elements?