That doesn't really solve the problem as there is no detail on any of the channels in the window or window reflection to recreate or enhance. The result is a darkening of the bright areas around the blown out window and refection, but that is not the problem. The suggestions above about highlight recovery from bracketed exposures works well, though my preference would be to simply light the room properly to balance it with the exterior, which would take me less time than doing the recovery in PS and personally I would rather spend more time shooting than sitting in front of the damn computer.
You're right, it didn't work.
FWIW, I try to use natural and/or installed lighting as much as possible, supplemental lighting is only a last resort to get the shot with one exposure. Heck, that image of the tiny living room could probably have been lighted with a single on-camera flash bounced off the ceiling to bring it's light value closer to the window, but what about a huge commercial space? Sometimes, it's just impossible to light a whole room so you have to use what's there, which is when these techniques come in handy.
I suspect though by looking at your (very nice) work that you know this, I'm just mentioning it because it needed to be said.
BTW, I still shoot 4x5 as much as possible and have a number of high power strobe packs, so I have a pretty good idea of what you can and can't accomplish with supplemental lighting. 95% of the time all those powerful lights stay in the back of my car. It's like the umbrella paradox: carry an umbrella if there's a chance of rain and it probably won't, but if you leave it at home it's gonna pour!
BTW, have you ever seen Adrian Wilson's work? (www.interiorphotography.net
). He doesn't own a single light, doesn't believe in them, and shot 6x7 film for 20 years before recently buying a 39MP digital system. Point being that it's not always necessary to either light an interior or do any exposure blending - Adrian built a lucrative career as an interior specialist without using either.