IMO, and i'm a Canon user. If you really want DR and it's the most impt bit for you. Go Nikon. Nikon definitely has better DR.

I would love the DR of Nikon but prefer the AF and WB and other niggles and jiggles of 5D3 over the D800.


But from what you're saying, GND filter and/or shoot raw and bracket it. Then merge it in PP.