The area within the current UK border that comprises the garden, maze, and surrounding tree-berm is half an acre, shown in the white box.
The area behind the UK comprises the roadway turnaround (which
@marni1971 said was going to be 'rationalised') and storage units abutting the IG Gondola Station is 1.1 acres, shown in the pink box.
So, you would have at most 1.6 acres to work with.
Trying to figure out the size of the attractions you asked for is difficult because they're housed in a large building. But I believe Mr. Toad is .3 acres and the entire building for Toad, Pan, and Alice is .6 acres. In the MK, Pan is .3 acres and IaSW is 1.5 acres.
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