Hi Julie,
The Fort Wilderness Cabins are located on the left side of the resort complex, with the campground facilities located on the right side. There are campsites that are close to the cabins but none adjacent to the cabins. If you were using a golf cart or bicycles to move around the property, the distance is minimal between the two areas, but not within a quick walk of each other. Without a cart or bike, the best way to move from the cabins to the campsites would be the internal buses. The buses are convenient and run regularly but would add to your ability to move from one group to another swiftly.
The cabins are designed to fit only up to a family of six. Besides comfort factor, I can not see more than six people fitting inside. The living room area has a murphy bed which will sleep two, and the bedroom a full bed, that can also sleep two, and a set of twin bunk beds. There is no extra room for additional beds or mattresses. The cabins are located right next to each other as are the campsites, another option you could consider is reserving two cabins or two campsites if you want to be next to each other. You are not able to pitch a tent next to the cabin area plus the area around the cabins is not very flat or designed for a tent and there are a number of trees and bushes.
A great place to view a copy of the Fort Wilderness layout is at
www.allears.net. Select accommodations from the top choices and then Fort Wilderness to your left. At the top of the Fort Wilderness fact page is a link for a resort map that will show the location of the cabins and sites. We loved staying in the cabin and have actually booked a return trip in the near future. Hopefully this option will work out for your family too.