Ok so I've got a all day BBQ piss up happening tomorrow and have got a 4.5-5kg brisket and 3.2kg butt from elsco ( really happy with quality) and 8 racks of baby backs from Costco, I've also got the normal stuff like burgers,sausages, wings and kebabs, I would like the good stuff to be ready for about 5/6ish. I'm ok with the ribs and pork but this brisket is already worrying me

going on the average cook time it could be between 10-12hrs not really confident on leaving it overnight has I've only done a couple of cooks on the new GMG so was thinking about getting up about 4.30am and putting it on then
What do you think guys? Any advice would be greatly appreciated
Cheers Dave