I think you could easily use Mary Poppins to create an E-ticket ride.
How about a dark-ride-spectacular journey through the film?
You could enter through a recreation of Cherrytree Lane, pop through a holographic chalk pavement picture into the Jolly Holiday. The ride vehicle could be a next-generation Omnimover that rolls on a Indiana Jones platform. You could speed up or slowdown that way, as well as add motion effects. Imagine joining the fox-hunt and horse race!
For the climax you could wonder accross the roof tops of London to Chim-Chim, then wind-up in the midst of the fireworks-battle before popping back into the Banks' house. For a merchandise tie-in they could have a kite-shop at the exit.