Wisconsin river offers some fantastic fishing. I'm under the impression Castle Rock has a good musky population. We have a place in the upper dells across the street from the boat ramp. Don't catch many giants but plenty of good walleye, smallies, crappie, catfish, and the occasional sturgeon.
As far as the original question, I say, if it has indoor plumbing I'll call it a cottage. If not, I'll call it a cabin