After some quality time with the plumber, he determined that yes, I could Just Barely relocate the washer to the North side of the basement, but it would have to be up against the stairs, not the north exterior wall. He also determined that if I ever want a bathroom in the basement, the toilet must be within 5' of the existing plumbing stack, which means the bathroom must be essentially right in the middle of this space. It appears I have two choices - either two rooms and a bathroom in the middle:
OR one room plus a very large bathroom in the southwest corner of the house:
The 2 windows in the bathroom seems a bit of a waste of the basement lighting, and would leave me feeling a bit Exposed.
If I go with the two rooms/bathroom in the middle concept, it appears I can squeeze in an office in the SW corner with the two windows, a media room in the SE corner, and a rather small bathroom. I'm liking that option.
I suppose I could put a small kitchen in the SW corner, and have a MIL, but that seems like a HUGE project.