Minnesota Wisconsin is on par with Iowa Iowa State.
I am not going to take sides with your disagreement with Metro.
I do believe the Iowa-ISU rivalry continues to get stronger and has an intense history. It is in-state, whereby Iowa-Minnesota is more traditional season-ending conference rivalry.
The ESPN College Football Encyclopedia, edited by Michael MacCambridge, 2005 ESPN Books, has the following listed as major rivalries for those under discussion:
Iowa - Most frequent opponent has been Minnesota. First played in 1891. Have met almost every season since 1901. Minnesota won first 12 games of series.
Iowa State - It is Iowa. Began in 1894, heated up in 1904 when ISU beat Iowa 2-0, the first time Iowa had lost to an in-state team in 40 games. Due to bad blood and feuding, the series was discontinued and/or discouraged by the Iowa Board in Control of Athletics, and the schools played only twice from 1921 to 1976. In 1968, a six year series to begin in 1977 was later terminated by Iowa, refusing to honor the last four years of the contract, but was forced to honor otherwise due to an arbitrator's ruling. Iowa leads the series 35-17 (through 2004 season).
So for Iowa, Minnesota is pointed to as their most traditional (or serious) rival. Iowa State may be the most dissed/discouraged (or having a history of avoiding play by mostly Iowa); and for ISU, Iowa is the biggest rival. Maybe ESPN could be wrong, but that is how it is viewed due to the description of its history.
Without getting into details here, the playing for the pig and all, Iowa and Wisconsin are listed as Minnesota's biggest rivals. Minnesota and UW have met 115 times, the most meetings between 2 major colleges.
For Wisconsin, it is clearly Minnesota, according to ESPN.
Maybe the North Carolina factor is working somewhat in the analogy to Iowa and Iowa State. North Carolina's biggest rival was Virginia until the 1950s, having played the season ending game each year. Then it became nearby Duke. But also close-by NC State is a big rival. For Wake Forest, beating UNC is their top preference, though the feeling is not reciprocated.