My experience: MF doesn't save you that much space. At all.

I started with MF (Pentax 6x7) and later on added a Super Graphic. The SG, folded up, is not too much larger than the P6x7. The lens stays on the SG when it folds, so no problem there. I develop with either a tray or a Jobo in my bathroom. My enlarger is on a cart I built for it, and stuff stows away inside the cart. (I've posted a picture in the sticky "improvised darkroom" thread.)

I'm guessing here that the biggest loss is the darkroom. You can still have an optical setup, and it takes about 30 minutes for setup or teardown. It takes about the same amount of effort to develop LF film as it does MF film, so no savings there. And if you use LF film, you'll have better quality in the other workflow.