@koliveri Disclaimer: I am not from Boston so my advice is based on having done a trip to visit Tufts, MIT and BU.
Is the order based on admitted students day schedules? The reason I ask is because if there is any flexibility in your dates and you are starting at Tufts, I would go to MIT next, followed by BU, Northeastern and Worcester. If you stay near Tufts you can stay at the same hotel two nights and go to Tufts and MIT. Move to a hotel in Boston for visit to BU and NEU. We’ve stayed at the Marriott in Copley Square. Plenty of options to choose from in Boston and you may want something closer to the schools. You definitely do not want to try to park near the schools. They are urban campuses so not going to have on-campus parking like a traditional college campus that has visitor parking.
You mention that your husband cannot walk far. I would check the box that asks if anyone will be in your group that will require assistance. I have a medical condition which can make a good deal of physical activity very difficult. I can comfortably walk 3 miles without any issue. I did have a difficult time at Tufts because it has a significant amount of stairs to climb.