I returned home Thursday from a family trip with 16. Ages ranged from 6mos. to 63yrs. Myself and one of my daughters had been before and we both enjoy the planning part of the trip, so we began planning at about 18mos. in advance. We booked our trip at 8mos. and booked our adrs at 6mos., and fastpass+ selections at the 2mos. time. I feel like we were extremely well organized and everything went smoothly. We held many family meetings to keep everyone informed and spent lots of time letting everyone know what was important for them to do and the reasons why. For instance we let them know long before the trip why we felt rope drop was necessary, and how taking time to go back to the resort in the afternoons is helpful etc. We also kept notes on what to take, and anything we felt would give everyone a great trip. We kept notes of the great tips/ideas from the disboards too. Then we made sure they all knew these things were only suggestions and they were free to do what worked best for their individual families. Which everyone did.
At some point before it was time to make fp+ selections we sat down as a group and explained how that all works and the importance of making your choices early. After everyone made their families selections and times they wanted them my daughter organized them all and send the info to our
travel agent. For the most part we pretty much had all the same selections and they all ended up overlapping by no more than 10 min. So at the end of each day we went over the plans for fp rides for the next day. Usually it worked out we all rode together but when it didn't it was no big deal. for instance we would say, "if everyone wants to ride safari together we will need to meet at 2:30". whoever didn't show up then rode at a different time. no big deal.
When making our adrs we requested two tables of 8 close together. We had one wheelchair and 1 highchair in our group. At some meals all the guys sat at one table and other meals we just grabbed a seat anywhere. It gave us a chance to visit with everyone in our group. We were always close enough to visit with either table too. I feel it worked out well.
Our group consisted of two families of 4, three families of two and 2 singles. We tried to make sure nobody had to ride or do things alone, but found out that at some times they actually wanted to go alone and do their own thing. We also didn't stay in our individual groups the whole time. Sometimes the kids would want to do things with grandparents, or cousins, aunts or uncles.
I wanted everybody on the trip to be happy ALL THE TIME we were there and I stressed that often. That did not happen, and really it is pretty unrealistic to expect that. We did have both crabby children and grown ups once in awhile. We all just did the best we could.
I think communication is the most important thing to stress when planning for a large group. People are not mind readers. We had one incident when one of our group members wanted to eat dinner at the castle instead of breakfast, but didn't express that until after the adr was made and by that time nobody really wanted to switch. One day I was so intent on not letting my son have to be alone I guess I was smothering him. Finally he pulled his dad aside and explained he didn't want to hurt my feelings but there were different things he wanted to see and do.