First off, rent a vehicle that can legally carry 9 people and will have room for your luggage. That would probably be a 12 passenger van. Second, get a GOOD night's sleep Friday night, leave at the crack of dawn or even before on Saturday morning if you are going to drive straight through. Do you only have 2 drivers? If you have 3 or more, use a proper rotation keeping both the driver and front seat navigator awake - switching off every 3 hours. If you don't have a 3rd driver, still switch off every 3 hours and use a non-driver for a navigator, switching them off too.

Do the same thing for the return trip, leaving bright and early.

Buck - it looks like they have a 4 day weekend - so this would be 2 full days and 3 nights there, taking a day to get there and a day to get back. I agree, this is not wise, but it's doable. May not be very enjoyable.