I would say Vanderbilt. Northwestern doesn’t really have a good premed program. My sibling goes there and says everyone that hopes to pursue premed/science when entering begins with their chem or bio class like all premed students do, and end up dropping out because it’s way too hard, and then sets a new path because now they think premed isn’t their thing. NU is more of journalism, theatre, english kind of place than science and math unless it’s graduate school. and yes, winter in Evanston is death. In addition, I had my interview for Vanderbilt, and it’s known as the happiest university in the nation with a no-loan system so that’s another thing. I didn’t get in though 
hope this helps!