A lot of stuff is still open. Tours are still available.
You can still get your drink on at restaurants, but you have to buy food, and cannot get to-go drinks.
However, two easy solutions are if you're not really hungry you can buy the cheapest appetizer or side on the menu. With that purchase you can sit there and down as many drinks as you want. Also, there are convenience stores all around where you can buy beer and liquor, go outside, open it up and walk around no problem.
Something I did one of the days was buy a $3 Jazzy Pass, which gives you unlimited streetcar rides for 24 hours. I think I rode the length of every streetcar line in the city, hopping on and off to check out cool neighborhoods, and grab a bite and a few beers whenever I wanted. I never waited more than 10 minutes when I wanted to hop back on the streetcar.
I also went to Harrah's Casino, and rode the ferry across the Mississippi.
I thought there was still plenty to do, and had a great time.