We stay at the cabins at Ft. W and we do the campfire at least once during our trip. It is a lot of fun - sing-a-long with Chip & Dale, roasting marshmallows, making smores and then watching a movie on the outdoor screen.
You can drive yourself to the Ft.W Outpost - same parking as HoopDeeDoo. Then take an internal bus to Meadows Trading Post. It is a short walk from the bus stop. If you are staying at a MK resort - then you can take monorail to Contemporary and then take resort boat to Ft. W. Wildnerness Lodge also has a resort boat to Ft. W.
You can buy roasting sticks (33cents each) and bags of marshmallows and smore kits - all pretty reasonably priced.
If you are going during the off peak times when the parks close early then this would be a fun night time event.