I think this is a very good match-up for Wisconsin. In general, a cocky major-conference team that thinks they will win on talent (rather than effort) has almost no chance of beating Wisconsin in the tournament.
Getting into the nitty-gritty, Ole Miss reminds me a little of Illinois. Like Illinois, they are a team that relies on threes but isn't especially good at making them. This is especially true of their main offensive threat, Marsall Henderson. He is an all-world chucker. For example, he went 3-18 against Mississippi State recently. From three. Yet he shoots just 35.7% on threes. So he will shoot, and he will take bad shots. Make him uncomfortable, but let him shoot, box out, and play the percentages.
On the other hand, he was 10-31 from three in the SEC tournament and Ole Miss still cut down the nets.
Like Illinois, Ole Miss is relatively soft on the defensive glass. In SEC games, opponents rebounded nearly a third of their misses. Systemically, Wisconsin emphasizes transition defense over offensive rebounding. But Evans, Bruesewitz, and Berggren are all wily seniors who know how to get on the offensive glass without fouling and without jeopardizing the transition defense. If the Badgers are cold—which is a prerequisite to any losing scenario—they can still win by rebounding a third of their misses.
Ole Miss has a chance: play zone and hope the Badgers build a house of bricks. If that happens, this is a 50/50 game. In that scenario we see the Badgers lose if they combine a cold-shooting day with Marshall Henderson getting hot and the ball bouncing Ole Miss's way on rebounds. But even if the Badgers are cold we could still see a comfortable win if they crash the class and/or stifle Ole Miss's offense—both of which are more likely to happen than not.
I'll take the Badgers, 68-59.