Jacob M did a version of that loop this weekend, but without Sun Prairie and most of Blue Mounds. He posted his route over on the Corp 100 Facebook page. I think it was 142 miles.
If you could overcome the logistics, a point to point route from CamRock to Blue Mounds would save some miles. Or, turn it into an overnight bikepacking ride and camp at Blue Mounds. Doing it all in one day would be a feat.