Ohio State vs UMN seems to be a pretty common decision for people to have to make! I know absolutely nothing about OSU BUT I do live in Minneapolis and am attending UMN next year.
What I can say is that the Twin Cities area is huge, you can find anything you want here if you're willing to drive to it. Public transportation exists, but is not ideal, though that might get better with the new light rail line coming in next year. Biking is also pretty big here - lots of trails and bike paths, and people use them year-round. Yes, even in the frigid winters. While the metro area is large, there are also tons of lakes and parks, and the UMN St. Paul campus feels like it's in the middle of the boonies even though it's most definitely not. It's right next to the state fairgrounds and a couple neighborhoods as well as a few fields. Weather here is something to seriously consider as well. It is April 9th and we are expecting snow tomorrow. That's right, it's still winter here, and it gets old VERY fast. I've lived in MN my entire life (minus one semester in college I spent in Australia) and long winters (not every year, last year we had 70s in March) can really affect your life and mental well being (it's depressing, at least to me). Also, shoveling snow is a pain and driving in it pretty much sucks. The summers can make up for it, but are usually wicked hot and ridiculously humid (thanks to all these wonderful lakes!). Also, mosquitoes. The spring and fall are usually pretty decent though, and in the summer all the lakes make for great activities (canoeing, kayaking, swimming, fishing, boating, water skiing, etc).
On the flip side, I do not know if you can get in state status in MN. I actually believe it is fairly difficult if not impossible to do so from what I've heard. And even if you do, the in state tuition is pretty pricey itself (UW Madison's OOS tuition is cheaper than my good old UMN in state tuition... makes me a sad panda sometimes).
Finally, I graduated undergrad with about $40K in student loans. This equates to monthly payments for me ~$500 on the 10 year standard plan. $500/month difference seems pretty large to me, but of course the repayments will be much different with the higher starting debt and all that. And from what I've read on here, $40K seems to be about the minimum cost difference between the two schools.
As much as I love Minnesota and am not questioning my choice of attending the U of MN, had UW-Madison offered me a seat instead of a waitlist number I would be seriously considering attending, even though the difference in debt would only be ~$24K at the end of it all.
Also, I'm 25 and will be 26 when starting school next fall, if it matters 🙂
All in all, I like the idea of making an Excel spreadsheet to weigh the differences. Good luck making your decision!