If I could, let me help you out with a visual.
This is an aerial photograph that shows the area of the Settlement as well as the campfire area. In this photo, I have marked the approximate area of the Settlement bus stop with a green star. The buildings that you can see just above the green star are Pioneer Hall, etc. The campfire area is marked with a red star. The clearing to the left of the star is the seating area, stage and movie screen. I have marked the 800 loop bus stop with an orange star, and the 1400 loop bus stop with a yellow star (this corresponds with either the orange or yellow bus routes).
Please note the legend in the bottom right of the photo. I would say that it is a less than 600 yard walk from the Settlement bus stop to the 800 loop bus stop. For comparison, I would say that the walk from the entrance of the Magic Kingdom to the castle is 300 yards. So, a walk from the Settlement bus stop to the campfire area is definitely manageable. If a bus isn't waiting for you at the Settlement bus stop, chances are that you can walk to the campfire before the next bus arrives.
From the 800 loop bus stop, walk across the street, and then across the foot bridge. No need to go all the way to the Trading Post and loop back. From the 1400 loop bus stop, walk in to the 1400 loop, and hang a left- you will see the campfire area after walking past about a dozen campsites. If taking the bus, take whichever one comes first- yellow or orange.
TCD