GCP I live in PDC and 2 of the supper clubs listed are on the list. The Black Angus which I'm not a fan of as it's more for uppity folks and is very expensive. The snooty folks tend to go there. The Barn is more my speed, environment and price, my wife and I like it there. We don't go often but once or twice a year. It's ironic you mentioned Bagley. I lived there for 12 years before I moved to PDC. It was called Luck of the Irish until about 4 - 5 years or so ago. It was owned by Tom and Lori Irish. It's now Lucky's and I work with the Dad of one of the owners. We both work 2nd shift and are the only 2 guys doing the job we do so we're working together everyday. Bagley's a resort town busy in the summer and pretty dead in the winter. The Cottonwood is also listed but I haven't been there in probably 30 years even though it's only 30 miles from me. My parents used to go there when I was a kid. They had awesome sirloin tips which were lightly breaded and friend pieces of sirloin steak. They were good.

I'll throw a nearby Iowa place in as well that classifies as a supper club IMO. The Old Rossville Store in Rossville IA. It's about 15 miles from PDC and they have really good Prime Rib at a reasonable price.
I'll add another IA one. The LIghthouse in Clayton IA, We went there on New Years Eve and had a very good meal. For the 2 of us the bill was $70.00. That's a steal on NYE.

The other thing that to me qualifies as a supper club is the salad bar that all the above offer. For me a good salad bar is going to be found in any supper club worthwhile.

I live right on the line between illinois and Wisconsin we still have a few but have lost some over the years.some good ones in the area,VILLAGE BAR,REDS SUPPER CLUB,LOUISBURG JUNCTION,3 MILE HOUSE AND COUNTRY HEIGHTS in no particular order.some we lost are ELMO CLUB,HIDEAWAY AND THE COACH&4 over the years.these are within a 15 mile radius from me.all serve excellent food.