I'm thinking it's gonna be over land like original tot
Gotta say I doubt seriously they would do it over a land mass. I mean, folks would just lure the Paragon high end critters away and park them a good ways away. I don't see that as being an option... I mean they turned the Paragon feature on in the dynamic dungeon specifically to give the event some real badasses that HAD to be fought.
Just my opinion on it though... ain't like I profess to know it all
or that I can predict what the current batch of game runners will decide...