Preview VR Window in Non-Stereo, Full HD for Video Capture

I have not been able to figure this out. It would be great to actually be able to capture true 1920x1080 16:9 widescreen footage of my game for trailers, promos, etc.but by default we get the single eye preview that chops off half the screen on both sides.

How can I get the preview window to show in full HD when playing in-game?