There is no propane filling station at Ft Wilderness. There is a Camping World with propane close by on 192, get a fill before you get to Disney. There used to be folks who would come to the site and replenish, for a fee, but Disney may have stopped allowing this as their policies have changed regarding service providers. Call the Ft Wilderness front desk and ask. You can find their number in a google search.
Thanks for asking the question Pirate! I was actually wondering that the other day as we are in need of a fill-up and are headed to Ft. Wilderness in a couple of weeks. Will make sure to get it taken care of before we go.