Northwestern is a private university. Your state of residence doesn’t matter one bit when it comes to awarding of need based aid…which is what they award.
If you have done the net price calculator with your family stats, then you should have an estimate of your aid, and net costs.
If your parents are not divorced, don’t own a business, aren’t self employed, or don’t own real estate other than your primary residence, then the net price calculator should be a good estimate.
If you have already done the net price calculator for Northwestern, what more would we be able to add?