I don't want to bombard this thread, but yeah, I've heard of the B2B. Haven't been on any part of it yet, but its technically made up of all roads, no off road tabs needed. Several off road and overland groups regularly have meetups, messages, and events for it, and I know of at least one shop, Zeus Offroad, that hosts an event 1-2 times per year that do the whole thing. 4-5 days I believe.
I sense a Delica B2B trip in the future...
PS there's a few other non-official routes popping up in MN with the ongoing overlanding crowd. Check out the FB Group 'Minnesota Adventure Trails'. Similar to the B2B, routes are generally made up of roads, albeit gravel, forest, and sometimes non-maintained roads. I've been meaning to check out the SEMAT, SouthEastern Minnesota Adventure Trail. Lots of camping options in the driftless area of SE MN, and not too far from the Twin Cities.
SEMAT Route Google Maps
Like with many 'overlanding' things the roads, camping options, and quaint towns have always been there; but there's a lot more resources available now. And its cooler