Please be very careful with him doing all the driving *and* driving during the night. Even though he has taken the day off, if he's not used to sleeping during the day he most likely won't get any extra sleep before needing to start the drive. And if you've been working all day, you most likely won't be able to stay awake to help keep him alert all night. And what's going to happen the next day when you arrive? Is he going to be so exhausted that he's just going to want to sleep all day...thus throwing off his wake/sleep schedule for the next day as well? If you manage to stay awake all night to keep him alert, you'll both need to sleep when you arrive. I know a lot of people do the overnight drive, but it can be a dangerous one if the driver isn't used to being awake and alert during the night. My son and his girlfriend did the all-night drive one year and they were exhausted when they arrived after a 16 hour drive. They ended up sleeping most of their arrival day which negated any advantage they thought they were going to have by driving all night. They said they'll never do that again. Now they drive 5 or 6 hours at night (usually until about midnight or so); get an inexpensive hotel and sleep for 5-6 hours; get up and finish the drive. They arrive late in the afternoon but at least they're rested and have the energy to drop their bags in their room and head straight to a park.
I've read other stories over the years of people thinking they're saving time by driving all night but end up so exhausted when they arrive that they end up losing a day anyway. To be fair, I also see people saying it works fine for them. Just playing devil's advocate/mom here.
The last thing you want to do is *start* your Disney vacation exhausted.