I discussed this with my Mrs last night and I think we are going to give it a go for our family and friends. Just keep it simple and do 2 big pork shoulders started off a few hours apart then get people in from lunchtime to early evening.
You can do it other weekends too as I have had to go for the weekend before as I'm out both nights and can't leave the smoker unattended.
We have gone for Sunday 13th of July which gives us plenty of prep time. I may even see if the Butcher will help out a little on the cots of the pork butts as it's for charity.