I've started going a couple of times each year for work. Never been during a gameday weekend, so I imagine it will be a different world for you. Ordinarily, it's a pretty chill city.
The Lambeau tour is worth it as is a visit through their team shop. It's incredible the amount of life in that stadium, even in the offseason. 1919 Kitchen is in the stadium as well and is a cool spot for a drink and appetizers. The food is pretty good.
The whole Titletown area west of the stadium is very nice and seems like it would be a blast on gameday. But I've not experienced that. It's certainly worth a walkaround on gameday. Hinterland Brewery is a nice spot with good food and just decent beer.
If you need to pick up groceries, the Hy-Vee is a ridiculously nice grocery store. It's almost worth a visit just because...
The cool nightlife spots are North Broadway on the west side of the river and the area right across on the opposite bank. That east side has Mangiare and Republic Chophouse for a nice dinner. Ned Kelly's Pub is nearby with an excellent and expansive tap list.
Over on broadway, you have a cool combo of breweries with Copper State and Titletown. Copper State wins on beer, Titletown wins on venue (especially with their rooftop patio). I've not eaten at Chefusion yet, but it comes highly recommended.
Cheesesteak Rebellion is a good spot for a quick lunch. And if you're into the diviest of bars, you've got a few blocks to choose from right there.
