I’ve gone back and added a little bit more to get the effect you were talking about. I wouldn’t say it’s perfect but it’s a start. I’m certainly no materials or post processing wizard so if anyone else with a bit more knowledge sees something wrong or wants to add to I hope they do! 
Here is the result I was able to get with the following tweaks:
Here is the tweak I made:
I added some “add” and “Multiply” nodes for some of the different scene texture choices. and for the constant value circled if you adjust it affect the brightness for the scene. Somewhere between 1.1 and 1.5 look pretty decent for test purposes. You would definitely want to refine to get the look you want. 
So here’s the vid for what I’ve updated.
The video seems a little choppy but I think that is just the capture. Really smooth on my end. For reference on the lighting that is baked. The first room with the chair has a default value of 5000, the other two are set to 1000.
Give a shot and post any updates you get. I’d be curious to see how you implement any changes and if you get a more refined version than my thrown together one here.
Edit:
Adding image for other users who may want to use and toggle it on and off easily. You can set up the following in the Level Blueprint to easily do so.
