Now I am in a dilemma, I have just bought a 12 Lb butt and there are only 3 of us. and have never cooked one before, go large or learn from my mistakes - decisions, decisions!
I suggest you smoke the whole thing. There really is no meat that freezes and thaws as well as pulled pork. Especially if you have a vacuum sealer. But works nearly as well in freezer bags carefully sealed with very little air. If you have the time that is. A twelve pounder will take you 24 plus hours to smoke unless you either smoke it hot and fast, which I never do, or foil it when you reach the stall, which only cuts a little time off. I would smoke it ahead of when you want to eat it. If you count on a Butt being done at a particular time you can and will get your BUTT kicked. Been there done that. Now if you want to cut your time in half cut the butt in half and smoke both halves at the same time. I am telling you it thaws and reheats just like you made it that day. There are a myriad of uses for pulled pork. Basically anything and everything. Bottom line is a Butt takes a long time to cook and be right. There is no reason to make mistakes when doing your first Butt as long as you use a tried and true recipe like this one.
http://www.smokingmeatforums.com/t/140055/boston-butt-pulled-pork-step-by-step I also suggest you make sure you have a good reliable tested meat thermometer and one for the smoker. That is even if your smoker has them already in there. The units they supply with the smokers commercially available are well known to be off by as much as 100 degrees. It is good to do your ground work before you even get started. The best way to get started off on the right foot is to start a post of your cook that day. Start it a day ahead would be even better that way we can
make sure you have all your ducks in a row. It really is easy if you have these things and follow this advise. Good luck and Happy smoking. Timber. PS; if you have any questions feel free to ask.