My husband gets migraines at least once a week, usually following a bad night of sleep. He has the sleep habit of a college student. A problem?

Yes. Migraine sometimes be precipitated by poor sleep, exhaustion, stress, food etc. He needs to take care of those opting factors and life style.
Yes, a problem. Pain is a warning sign from the body that something is not right. Migraines are painful, hence something is not right. If what causes the migraines is known, eliminating it usually minimizes the migraines. So, if your husband's sleep habits are the cause, he needs to change his habits or he will continue to suffer, and it may get worse.