Detroit could be a soccer town I think. I'll admit it's a longshot, but consider that Detroit is a huge metropolitan area - despite the hollowing out of the city, there are still 4 million people in Wayne, Oakland and McComb. Additionally, there actually is a large international presence in Detroit - I've felt like it's one of the most cosmopolitan cities in the Midwest, behind only Chicago. "Mexicantown" isn't populated by WASPs, and Detroit does have a significant population of 1st generation Eastern European immigrants. Add in the fact there is a large arts community in the city - I imagine these guys would fit the "hipster" bill posited above - that Detroit is an incredible sports town, and has a large number of Fortune 500 companies, and I could see a 30k seat soccer stadium turning a profit.
As for building this...as the links say, the cost would be "astronomical." Turning it into a two-story facility would mean you'd need to beef up the footings - which essentially means you'd have to tear it down, rip out the old concrete, and pour new footings and foundation. As said above, you may as well do it from scratch. You pretty much are anyway.