I say get up early. I've never tried an all-nighter, as I need to either A) get a remote thermo with an alarm so I can monitor temps while I sleep, or B) do it sometime when my son isn't home. I wouldn't want to do it without being able to take a nap afterwards, and, well, I'm his favorite. If he's up, I'm up. He makes sure of it. Don't get me wrong, I love it, but I'd want to be able to take a little nap, and that may not happen with him there.
Sounds like my wife needs to take him to see her mom!
I did, however, get up at 4am on Super Bowl Sunday to start my brisket. I'd recommend just getting up super early, though with that much meat I'd either cut it in half, or go to be early, then get up at about 2 to start it. Even then, that's only 15 hours (if you put it on the smoke at 2) until you want to eat. That big chunk of meat may be cutting it close, or not done in time. I think all nighter is your only option.