Um... if your smoker runs steady enough do the pork butt overnight. Once it is done you have two choices 1) wrap in two layers of heavy foil, and then put them in a cooler lined with old towels and towels on top to fill the dead space. They will hold temp in a cooler for 5-7 hrs. no problem (still be to hot to work with bare hands). If you cooler them that long though pull the butts off when they hit an internal temp of 195°, then the cary over cooking won't turn them mushy. 2) Second option is to smoke them this evening for 4 or 5 hrs., then wrap in foil and toss into a 225-250° oven. After that same scenario for cooler time/technique.
If you still don't think you can do pork butt, I would suggest doing some 3-4 lb chuckies (chuck roast). They usually cook in about 6 hrs. or so. Same technique as pork butts, take to 165°, foil w/liquid, take to 185-190 for slicing or 195-205 for shredding.