But you cannot take your 42in TV with you in a backpack. Mobile setups are more practical than fixed ones for most people.
Though with the power consumption required for a VR GPU display, you'll likely need a decent-sized battery pack (maybe on your belt), for this not to be tethered to a power outlet.
For this product space, I think I personally would be happier with a AR style solution, though that comes with its own challenges.
I've got to wonder if a CastAR / Tilt5 AR projection system would work better for working. You could certainly roll up the retro-reflective "screen" into your backpack.