Recyellow, I think you've got your answer but I'll throw in my experience.
I cater and have to have meat on demand so I use a foodsaver to vacuum seal and then freeze. I pull the butts just like I would be serving them immediately and portion in no larger than 3# bags. Once sealed, I drop them in ice water until they are cool and then they go in the freezer. They cool faster in water than in air so you get through the 'danger zone' quicker. Reheat in boiling water and serve when you need it. If you pull them while they're hot, you get all the fat and juices so no need to add anything (unless you want) to keep the meat moist when you reheat.
I agree with cynfulsmokersbbq, you can't tell the difference between fresh and frozen if you do it correctly. I've even challenged people to tell the difference and they can't.
Good luck with your event, I hope some of this helps.