Samsma - that's exactly what we did last December and what we will do again this year. We love staying at the Wilderness Lodge because of the wonderful theme, architecture, restaurants, Christmas decorations, etc. However, we do enjoy some of the activities at Fort Wilderness - like the campfire, hayride, carriage ride, Mickey's BBQ, petting zoo and stables, etc. We have always found it really easy to get back and forth. There is a nice walking/bike trail running between the lodge and the campground. In fact we rented bikes and rode over to Fort Wildrenss several times - and we definately are not expert bikers or in the best physical condition. It was an easy ride. We walked it several times, too. It was very pleasant and shaded. There is also a boat running back and forth between the WL and FW. We never found it a problem getting back and forth between the two. I felt like we had the best of both worlds. We did check out the cabins, but we felt they weren't really for us. We would have missed all the theming and luxury of the lodge. Plus, we wouldn't have used the kitchen because I'm not about to cook on vacation!
You don't need to go to Fort Wilderness to see the water pageant, though. It stops in front of the Wilderness Lodge, too. In fact, we had a perfect view of it from our WL balcony. You can also go down and watch it from the WL boat dock.