Yeah, god bless VC. The most I've ever walked around with is 2 backs for colour (RVP and Ektar), and 2 for B+W (PanF/D100/FP4/APX and HP5/TMY/TX, sometimes an extra back with D3200 depending on where I'm going and what's floating around the fridge on the day), that covers almost all lighting I run into. But that's only because an extra Kiev back costs as much as a roll or two of film so why not?
I'll admit to not really practising N+/- routines religously, the closest I get is when there's too much range to capture I switch from RVP to Ektar, or on B+W I'll just rodinal-stand it to get all the detail I can without blowing out.
One day I'll have to learn how to use the Zone system properly when I start coating my own paper and am stuck with a single grade (unless I just buy Rollei Black Magic VC emulsion, but that's damned expensive and I'd rather mix my own).
Speaking of using MF as LF, how about the Fuji GX680? It's practically an LF camera that takes rollfilm, more movements (and heavier) than an RB, afaik you can crop to 6x8, 6x7, and 6x6, and the lenses are as sharp as any other EBC Fujinon. And they're so unpopular these days that they're practically giving them away on fleabay.