If i remember correctly from interviews, Case lectures aren't required and most students just find them supplemental to the PBL stuff they all seem to love
I would go to a place that currently has faculty in a field you're interested in. Previous success in that field doesn't help you if those people are no longer there. In addition, I would go to a place that can match you into a residency you want (if you are undecided, a place with generally good matches in everything) in a place you want.
And as far as weather goes, Cleveland and NYC have similar winters, both warmer than MN