Looking from the aerials, and from what I can..guess,
Mario Kart is looking to be about 1.56 acres, as it will inhabit the former lots of Soundstage 28 and 22-23.
If somehow, Panda; the Studio Store and restrooms stay (but Studio Deli goes), it'd give them potentially around 1.83 acres.
That'd be about 3.39 Acres. For reference, Hogsmeade clocks in at 6 acres.
Nintendo, will have the benefit of being a multi-level structure; but it's going to be fascinating to see how much they can cram & cut.
EDIT: Coming in again, but this is what it could..fesibly look like, if they went with getting rid of Panda/Studio Store/Restrooms..
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