Approaching it “photographically” is probably a bit more deceptive than you might realize. A pro photographer would/could approach that kind of lighting situation a number of different ways, but in this era you can be sure many if not most would realy on compositing multiple exposures to get the right look.
In your case I would suggest you decide in advance how much exposure control you want in the window - if you want to see detail in there (of any level) then set your exposure by the window and fill the room to match. The old school way (photo) might have been to use neutral density filters taped to the window to bring that value down a bit, but as it is a key light source you don’t have a ton of option except to balance exposure to that.
Using large pure white light sources will always give you fairly blah lighting in a room ful of diffuse materials (bed/walls/upholstery etc.). You might need it for overall fill, but if you want to get away from the flatness issue you need to add more directional light, and probably some smaller and harder lighting sources.
Adding some of those lights with different colour balances (e.g the nightlights can be on and use a warm colour temperature) will also help add some variety and depth.
Bear in mind also that much can be done in post, and photographically very often is, but it will need to be done selectively, not globally to add depth and contrast (e.g toning down one wall and the side of the bed to add direction to the light as well as contrast, rather than just level/curves to the whole thing -- etc.)
Last: I believe that you can’t use Vray tonemapping like Reinhardt with linear. That only works on non-lwf images. If you want linear then you need to do the tonemapping in post.
/b