Whysnow is right there are some good places near I/O, including the Weary Traveler, which is probably a mile down the road, but worth it. Great beer and amazing food. It’s somewhat eclectic and the best of Madison in several categories. I like the carne asada there.
If you want quick, but really good then burrito drive will deliver to I/O...
Blue Moon has killer burgers no doubt and great games just like I/O.
Heck, hit both, but I/O will be on your way and closer to the Alliant as they are both off of Lake Monona.
Remember, Wisconsin hosts Michigan in Football Saurday so it will be insane and a lot of traffic downtown...have a great time and enjoy Madison!