My first year I was on campus about every day, we had a lot more "mandatory" things, but I did not attend our medical knowledge lectures (these are all recorded; I prefer to watch on 2x speed). Second year, they're more lenient, I would say I was on campus about 3/4 times a week, mostly because you have a nice quiet space to study, the Biddeford location had a dining hall, etc.
I will say, I think it'll be great to be on campus at Portland, you guys have an extremely beautiful new building you get to be in! Plus, there's a ton of great food options around the area, but if you prefer a cafe to study in, Portland has a ton of those.
First year you will be on campus a majority of the time because you will have in-person anatomy for about 8 hours a week, plus lecture, exams, etc.