Commuting, especially considering your goals (which will require you to be on campus or near campus extensively), especially with the treacherous weather… really is suboptimal.
Without the name of “Dream school”, we can’t evaluate if it’s worth it to borrow for rooming costs and without your EFC or other information nor the rooming costs you’d have to borrow, it’s hard to evaluate whether it’d cause an undue burden on your family or if they could weather it.
It’s especially complicated because as a premed you should be involved with on campus activities (volunteering especially) where you’ll need to be seriously involved by junior year, which would require you being there all day long. Also, as a parent, I’d be very worried about you driving at midnight after a full day of classes and work and labs and study groups.
BUT most students whose intention is to be premed don’t make it into med school so should you decide based on med school? If you change your mind and switch to another major or goal, then you might not have to stay on campus as much. Then of course, you’re thinking of not borrowing for dream school because you’re worried about borrowing for med school, but if like most students you don’t actually make it to med school will you feel you should have attended dream school since you sacrificed it for a dream that didn’t come true?
If one of the 7 colleges you got into is less expensive than dream school but allows you to live on campus, wouldn’t it be a good compromise?