Hi Michelle,
Thanks so much for visiting the Disney Parks Moms Panel with your question. I definitely encourage you to attend the
Hoop-Dee-Doo Musical Revue! It is a really fun experience. The entertainment is boisterous and funny, and the food is delicious. My family and I love to take in this dinner show.
Taking a boat from Magic Kingdom Park to Disney's Fort Wilderness Resort & Campground is a great idea as a way to get to the Hoop-Dee-Doo Musical Revue, which takes place in Pioneer Hall. The boat will dock at the Settlement Area of Disney's Fort Wilderness & Campground, which is where Pioneer Hall is located. As to getting back to Disney's Saratoga Springs Resort & Spa, reversing how you got there should work. Take the boat back to Magic Kingdom Park, and then catch a bus back to Disney's Saratoga Springs Resort & Spa.
Sometimes, especially after the latest show of Hoop-Dee-Doo Musical Revue, you may see that there are buses waiting to take guests back to their Disney resorts. These buses may go to multiple resorts. You can always ask a cast member if these are running on the night you attend. If they are not, the boat to Magic Kingdom Park followed by a bus to Disney's Saratoga Springs Resort & Spa is a good idea.
I hope that this information is helpful for you, Michelle! Have a great time planning your vacation, and please do not hesitate to ask if you have any further questions.