Where would MSA clubs play in real life? Most teams would play in D2/3 college football stadiums, or large high school stadiums. Here is where the MSA clubs would most likely play if they existed in our world.

The Minneapolis Teams:
The Mills FC, Parade Park, Minneapolis, Capacity: not many, but it has space for temporary seating.
Minneapolis City: Edor Nelson Field, Minneapolis, Capacity: 1,400 with space for expansion
Dinkytown SC: Huntington Bank Stadium, Minneapolis, Capacity: 50,805

The St Paul teams:
Pigs Eye Landing SC: CHS Field, St Paul, Capacity: 7,120
Fairgrounds Club: Minnesota State Fair Grandstand, Falcon Heights, Capacity: "Around 17,000" (This used to be a racetrack, and is now a grandstand with space to build a stage for concerts. I imagine they could build a soccer field in front of it though.)
Club Rondo: Seafoam Stadium, St Paul, Capacity: 3,500 (Allianz Field is across the street)

Everyone else:
The Cities FC: TCO Stadium, Eagan, Capacity: 6,000
Edina Athletic: Kuhlman Stadium, Edina, Capacity, 5,554 (You couldn't fit one more person?)
Lift Bridge SC: Pony Stadium, Stillwater, Capacity: 4,000
Duluth 1857: Griggs Field at James S. Malosky Stadium, Duluth, Capacity: 4,000
Med City AC: Mayo Field, Rochester, Capacity: 3,570
Napoleon Athletique: Husky Stadium, St Cloud, Capacity: 4,400