I tried out a different spot in the house this morning. I'm looking forward to going full frame, because it's a little tight with my crop + 50mm. But I liked the results with the lighting. He wasn't being very cooperative, but at least I can see that I can get some nice lighting, and still keep my horizon (baseboard) straight.
Here's my previous spot. The only way for me to get around the slanted baseboard is to use the ottoman and take a half-body. And I really have to watch the angle toward the window, or I get too dramatic lighting (like in this one).
The new spot. This is looking straight on at the window, which is a tiny bit off to the camera right side. There's a wall directly to the camera left, that is creating the shadow on that side of his face. I'm able to keep the baseboard straight, yet still get shadowing/directional light.
And a couple extras
This one was pretty overexposed SOOC since I wasn't paying attention after I moved him a bit. At least I got very minimal noise at ISO 1600 Unfortunately, his face looks "hot", and I'm too lazy to put in the effort to try to fix it.