The first order of business in answering this question is to address whether Northwestern is going for the win or for the tie.
NU's non-conference schedule is relatively easy this year, so they'll be expecting to win most of those games. That means, in a late-game situation such as the hypothetical one mentioned in the title of this fine article, it's in the 'Cats best interest to extend the game into overtime, where they will feel like their superior team should prevail. It's the law of averages- the longer the game goes, the more likely the better team is to come on top. So, in the first 13 games of the year and in Big Ten contests against Rutgers and probably Penn State (though the Big Ten Media disagrees) NU will look for a two-point bucket in these scenarios.
In the vast majority of Big Ten games, however, the 'Cats will be underdogs. This changes the mindset in these type of situations completely-- if you feel like you're the worse team, you want to end the game quickly, "steal" it per se, by going for a dagger three pointer.
In either case, it seems that Tre Demps is the natural late-game option. A shifty guard with a neat handle, Demps is simply the best the Wildcats have at creating his own shot, and showed no hesitation in doing so last year. He also seems to genuinely enjoy the big moment, having hit multiple clutch shots last year largely due to his ability to, as mentioned above, create enough space for himself to get a clean look. And that's what you need in late-game situations. Demps had this to say about why he feels he's so effective in the clutch: "Growing up, my dad and I would always play one on one. At the end of the games, that's really what basketball is- you making a play. You're not going to get back door cuts, easy buckets. It's going to get a lot tougher. I'm just comfortable in that moment, it's something my dad and I worked on for years."
Demps has the right skill set and the ideal mindset to be the go-to-guy in late-game situations.
On another note, an interesting option for a late bucket that probably won't be explored (Collins loves to play through his guards) is Alex Olah. Yes, Olah has been tentative at times and hasn't been an offensive juggernaut by anyone's standards, but the part of his game that improved most last year was with his back to the basket in isolation situations. A solid seven-feet, Olah isn't really going to have to worry about getting his shot blocked, and he shot an improved 68% from the line last year- good enough for defenses to feel like they can't just hack him.
JerShon Cobb is a third solid option with the game on the line. It'll be interesting to see how Cobb looks physically after his meniscus issues (though Derrick Rose sure looks springy after his bout with a similar injury), but he's NU's top returning scorer and has a very smooth jumper. Cobb led NU in three-point shooting percentage last year at a respectable 35% on 4.3 attempts last year, so if an open look presents itself and NU has a chance to steal a game against a superior opponent, Cobb just might be the best option.