personally, I think this should go in Q talk to get more views.
Just a couple of my thoughts:
1) your cooker is part of your "problem". If you had a WSM (or a number of other cookers) it could run for hours and hours unattended. Not saying you should buy a new cooker, but this issue does not exist if you do not need to feed a pit.
2) Brisket and pork will hold wrapped in foli in the cooked state in a warm ice chest for 6+hours. If you timed the meat to be done before socializing times, it could hold while you are having a good time.
3) Pre cooking is definitely fine, as long as you know your re-heat schedule. I have precooked, sliced/pulled, and frozen in vacuum bags weeks in advance of social gatherings like the one you describe.
4) Not sure what cuts you are cooking, but brisket and pork in the smoke for a few hours, and then finished in the oven is more than acceptable.......