I like the idea of a Wye. But, those do eat up much more space quickly than you would expect. I wanted to put one in a visible area on the Glacier Line and realized quickly that even to turn a small snowplow it would stick out in the aisle about four feet. That's when I opted to build my scratch-built small turntable.
I'm still trying to envision your space. I see the door to the train room. I was thinking you might be able to maximize your space by "stacking" both "ends" of your line in your original space which would become a "hidden" area; complete with staging for both ends of the line. The main could follow along the walls in the "new" area at no more than 30 inch depth and be a very long grade...your have a much longer run!
I'm still trying to envision/understand the space.
