Thanks for your input. Adding to what you've said, I've read and heard on some occasions (from professionals in my sector) that taking some CS classes as electives was beneficial and wasn't too overwhelming.
It doesn't really matter much how much I value a diploma, unless I a hiring manager and you are a candidate and that's the typical case. Diplomas are meaningful culturally. If you already have a piece of paper to hang on the wall your calculus may be different than if you don't. That's ok either way.
If you have a diploma, then Coursera's MOOC's are a middle option. There is the formality, at least in some offerings, of a fixed course schedule and consequently a peer cohort and clear instructor student relationships. And it offers some excellent courses by excellent CS teachers. But it's not going to get you academic credit if you might really want a degree at some point.
I've taken a bunch of them and gotten a lot out of it [I've also dropped a lot of courses when I haven't]. But my situation is my situation - that's why I described it - and not your situation. Or YMMV.