I can see what you'd ideally like, but it is a long time away. It will take forever to get to the stage of having an (almost) complete VR experience but with your real body and a few chosen items (keyboard, controllers, body, etc) in there too.
No, it's already here, that's why AR would be so fantastic for Elite. Check out CastAR - if you were running Elite on it, all you would do is put some retro-reflector behind your control console (ie wherever you'd see cockpit canopy - above and around you), put the IR lights in the cockpit, and you're done - it then has everything it needs to put the sky above the physical cockpit. Depending on your seating arrangement, if your seat is too low you might need to peer over your console to see some of the in-game instruments, but that's just seat position.
(I've briefly used a CastAR prototype. It seems like they're (wisely) focusing their efforts on uses that VR is completely incapable of, so games like Elite are probably low on their priority list. But the point is, the capability exists, and it seems to have the potential to be the best way to experience the game).
And it sounds like the HoloLens might be even simpler - as described it already 3d-scans and tracks the area around you so it can integrate graphics into your surrounds. That's already far more sophisticated than what Elite needs - Elite support could be as simple as giving it a radius - "everything further than 3 feet away is gamespace."
Worst-case scenario: If you bring your hand up in front of your eyes occluding the gamespace, I assume the HoloLens will struggle with that (rough edges) or ignore it, but that isn't an issue because it won't happen because everything you do with your hands - flight-stick, note-taking, snack-munching, nose-scratching, everything has your hands below your eyes and in front of the realworld cockpit. There is no reason to be reaching into the AR rendered space above and around you.