Interesting question - given that the end result is supposed to be a low-poly game asset, I don't expect it to hold up super well for close-ups. So it may not be worth the effort.
Still, for the larger, detailed windows, I think I'll probably experiment with that and see if I can get some rooms in there. The typical smaller windows won't have rooms, even though I've found it pretty impossible to lend them any impression of depth by just painting them. I think the key there will be to experiment with subtle variations in color, and in the amount of output in the glow map, for each window.