Hi Heather!
What a fun evening you are planning! Whispering Canyon Cafe at Disney's Wilderness Lodge has a fantastic dinner and the kids always have a great time playing along with the server's shenanigans. You can catch a ferry boat from Disney's Wilderness Lodge that will take you over to Disney's Fort Wilderness Resort & Campground. From the marina, you will need to board an internal bus that will drop you off at the Meadow Trading Post where the Campfire is held.
Chip 'n Dale's Campfire Sing-A-Long is a favorite for me. It's such a fun activity to do as a family and it's complimentary! We visited the chipmunks just a couple of weeks ago. We just can't get enough. You can roast marshmallows by the two fire pits while you wait for the festivities to begin. If you don't want to bring your own s'mores fixins, you can purchase a kit for around $10 at the Chuckwagon Snack Bar. A guitar-playing cowboy will take the stage and play some familiar songs and then out come Chip 'n Dale. They will make their way around to each guest for photo opportunities and then join everyone by the stage for some dancing fun. It's a fantastic character experience! Afterwards, stay for the movie under the stars.
Fort Wilderness carriage rides last about 25 minutes and are continuous from 6:00pm until 9:30pm. (Times are subject to change without notice) You could squeeze in a carriage ride at the end of your night, but I wouldn't want you to feel rushed. You can make reservations for a carriage ride up to 180 days in advance.
After your Fort Wilderness fun, you can take a ferry boat back to the Magic Kingdom and then board a bus to your resort.
Have a magical day!
Leslie