Even at midnight I can't imagine there being less than 100 people working at the WH in various capacities. While it's probably not the duty/desk officers in the Situation Room/Security Council, there are plenty of maintenance staff that work at night. 5-midnight seems like it overlaps perfectly with a shift schedule.
But how many of them would risk their job by smuggling in a device that violates government policies? Every device in the White House should be accounted for and meeting a number of security criteria. There are really only two or three people there who would know that those rules don't apply to them.