I figured LS to be too small, but, what about using the entire MK for a KP style activity? You could have 1 or 2 missions per land. And each land will have a mascot that fits that land help you in the missions.
LIBERTY SQUARE: Could be Tom Gates, or preferrably someone who was alive during the time period.
ADVENTURELAND: Indiana Jones
FRONTIERLAND: Davey Crockett or Tom Sawyer
FANTASYLAND: King Arthur, Mr. Toad, or maybe the mice from The Rescuers
TOMORROWLAND: Tom Morrow, Timekeeper, 9-Eye, Buzz Lightyear
TOONTOWN: Mickey since it is his land
These characters interact with you through the communicator. I am sure Disney can fit the stations to blend in nicely since they pulled it off in World Showcase with KP.