Terrain Detail 6k'x4k' what resolution for heightmap and land should use? arc vis animation

6,000’x4000’ is the land i want to make, this is not for a game for arc vis animation. what heightmap resolution would be good, and what terrain size and detail would be good to make in UE4? We will be pulled in very close human 1st person in some shots in a couple areas, and far away in some other animations. is there a way to locally tesselate?? no correct should i got with 8149 is that maximum? thanks!!

edit sorry I am very confused as to how to get the distance right so that the number of grid equals the proper land size and how many sections, sections per componet, number of componet and overall resolution to make it as well.