I've read that the marshmallows are at 7 or 7:30. Not sure which. I also looked into the golf cart rental but you have to be a disney resort guest and you have to rent it for a whole day. I'm thinking we may just take a wagon ride and walk the kids around a couple loops that the wagon ride misses.
kace308,
At Christmas time, the campfire singalong (meet Chip & Dale, roast marshmallows, and sing along) begins at 7pm and the movie that follows every single night is about 740pm. The singalong times change during the year when you move clocks - in March it moved to an 8pm start and all thru the summer and in November it rolls back to a 7pm start (when we turn the clocks back). Here is the December 2015 movie/campfire schedule as an example:
As far as renting a Disney golf cart, ajenks22, Disney only rents them "by the day" and the day is coordinated to the check-in and check-out times for campsites at the Fort. Officially, rentals begin at 1pm (the earliest check-in time for campsites) and are due back by 11am the next day (the latest check-out time for campsites) the next day. If you come over and use it for a few hours, you will still be charged for a full day ($59+tax).
There are 3 internal bus lines inside the Fort that run from the beach/Trails End/Hoop Dee Do end ("The Settlement (Bus) Depot) to the check-in area end ("The Outpost (Bus) Depot"). The lines are Purple, Orange, and Yellow. Orange and Yellow can be gotten at the Settlement Depot and can take you up near the Campfire singalong. Your bus driver can advise which stop to use.
There is a Conestoga wagon that is the concession stand just behind the bleachers at the campfire singalong. They sell a Smores kit for around $10 (some graham crackers, marshmallows, Hersheys bars, and sticks) or you can BYO or just get a small bag of marshmallows and sticks (cheap option). You can also walk through some loops to see the camper decorations or see the Electric Water Parade down at the beach or the fireworks over the MK (music is piped in).
There are 21 camper loops to see decorations so my advice is to just plan on seeing those that are convenient to wherever you are or will be.
If you have questions, let us know.
Bama Ed