Hi there, Heidi!
Yes, you most certainly may use
water transportation to get from Disney's Grand Floridian Resort to the
Hoop-Dee-Doo Musical Revue. It sounds like a delightful way to reach your destination. I love that ride across Seven Seas Lagoon and Bay Lake.
Start your voyage by boarding a small water launch with a gold flag at the dock behind Disney's Grand Floridian Resort. Disembark the boat at Magic Kingdom Park. Ride the monorail one stop to Disney's Contemporary Resort. Explore this iconic resort to your heart's content and then board a water launch with a blue flag at the dock behind Disney's Contemporary Resort. If it is after 3 p.m., that small boat will take you to Disney's Wilderness Lodge. You must allow yourself time to explore this Pacific Northwest-themed deluxe resort. It is my favorite hotel in the entire world. When you have finished wandering through Disney's Wilderness Lodge, board a water launch with a blue flag again. This time it will transport you to Disney's Fort Wilderness Resort. Pioneer Hall, the site of the Hoop-Dee-Doo Musical Review, is just a short walk from the dock.
If you want to omit the monorail portion of the aforementioned pathway, take the water cruiser with the green flag from Magic Kingdom Park to Disney's Fort Wilderness Resort. Then transfer to the smaller water launch with the blue flag to explore Disney's Wilderness Lodge and Disney's Contemporary Resort before or after your dinner show.
It sounds like you have an amazing afternoon and evening planned. Take plenty of pictures and please enjoy some strawberry shortcake for me at the Hoop-Dee-Doo Musical Revue.
Sending best wishes and pixie dust,
Jill