Just do it. Plan for it and make a day of it.
Probably won't help you much in the short run but if long cook sessions don't appeal to you, build a UDS. I do briskets on mine. I light the drum about 9 pm and get it stable and happy. Put the brisket on about 10 or 11 pm and go to sleep. If there is an issue, the ET-73 will let me know. More often than not, I'll wake up at 6 am, go check on it and it is still cruising at 240ish.
When I do butts, I do get up early in the morning. But once the drum is happy, I can nap or hang out or whatever. It runs on autopilot pretty well.
So what did you tell her? Because my wife is wondering the same thing.