Some second semester staff will have to be back early. And yes it can take awhile to get a room unlocked because duties are basically at a minimum and there is one guy running around Bancroft unlocking doors for folks as they arrive and call for their rooms to unlocked. They don't like to do mass unlockings until duties are back in place at the company level. Mother B is not small.
Ask your kids if they can stay in Bancroft. If they are Plebes they can ask their upperclass. In the past it has never been an issue, doubt it would be this year. Mids always have an option to remain in Bancroft, it is technically their home. It can suck to be in transient during the summer (but if they need a rack, there is always one) but during academic year leave periods this usually isn't an issue as they can stay in their rooms. As a basketball player I rarely had holiday leave and asked for my room to remained unlock so I could come and go as needed. Was never an issue as it was coordinated ahead of time. Best source of info for all this is your kids. Leave schedules will vary based upon their finals schedule, ECAs, billets, watch schedules and even class year.