Hi Fred!
Wow....this sounds like quite the family reunion you will be planning for your next Walt Disney World vacation. Staying at the
Fort Wilderness Cabins is a perfect location to get everyone together and enjoy your surroundings.
Friends will be allowed to come into the park with the exception of a few very busy times such as Halloween. Your family and friends will need to park in the lot at the front of the resort and then take the internal bus to reach your cabin loop. They may also park and then walk to your loop if they choose to do that as there are sidewalks throughout this resort.
You are allowed only two vehicles at each cabin site. Each cabin will have a deck with a picnic table and then a small grill at the bottom of the deck. There is an outlet on the deck if you need that. You may use the surrounding area of the cabin as long as it doesn't infringe upon any neighboring cabin. Some will have more space then others.
A better idea is to use the common area near the main pool and Bike Barn. Here you will find a large covered area with many picnic tables as well as several grills. It is a great place to host a large group gathering. Last year there was one family who set up and decorated for a child's birthday party. It is a perfect spot since you have a large grassy area where kids and adults can enjoy soccer, volleyball, kickball and anything else. It is next to the pool and close to where you can rent the canoes and kayaks if guests wished to do those activities.
There is no parking at the pool so everyone would need to use the internal bus system which is easy and convenient.
I hope this gives you some ideas and possibilities as host to your family get together.