I think a really cool layout could go like this, it's much like 2004. In order:
Entrance at USF
Production central scarezone
House at SS 22
Hollywood scarezone
Central Park pumpkin forest
Kidzone Parade building house entrance
Sprung tent 2 entrance by M.I.B gift shop
Disaster! entrance scarezone, Distaster! queue house
NYC scarezone (includes sting alley)
Crossover at NYC library facade to Posidens Fury entrance (2004), scarezone in between.
SS23 house entrance at Posidens fury
SS20 house entance at Suess landing crossover gate
Carnage warehouse house
Toon Lagoon scarezone
JP scarezone, Discovery Center house
Bridge back to IOA crossover area.
So thats 8 houses and 7 scarezones, and the only islands used would be Lost Continent, Toon Lagoon, and JP which is still plenty.