The health insurance is easy. They can live on the moon and still be on their parents’ health insurance until they are 26. They may not find any preferred providers on the moon, but they are covered.
On the registration to vote in my state, it said that the applicant had to be a resident 22 days before the election. It reminded the the law said residents had to change their drivers license within 30 days of becoming a resident.
Most schools don’t care where the student lives for financial aid, but where the parents live. My state only gives aid to residents going to schools in the state.