Moving crew
So it is actually up to the President’s family to organize their own moving team that will help them get all their stuff packed and shipped to the White House. The moving crew can enter, set everything up, and then must leave. We guess it’s all part of the security they follow.
After the first family moves in, then everything falls into the hands of the staff that works at the White House. Trusted employees who have usually been there for quite some time and have been cleared by the secret service. This just sounds like a lot of work already for everyone.