Can you do away rotations in your MS3 year? Also is it impossible to schedule say a week off to visit family member with deteriorating health without major setbacks in MS3 year?
At my school you would not be allowed to do an away rotation MS3. I would be surprised if that were allowed at any school. Also, with Covid, most places have suspended away rotations even for MS4s.
As for your second scenario, my school would have found a way to make that happen, although it might have involved skipping my MS3 elective block or otherwise making up core rotation time. Just depends how flexible your school is.