Terrain Quality Restricted to Size?

Hey Community,

I have a question regarding the relation to a landscape size to its quality.
My plan is to create for a small project a small terrain like just one component with 256x256 resolution.
But is it possible to make a small terrain with the quality of a huge one?
Id like to sculpt the terrain in Mudbox, render out the heightmap and send it to World Machine and export the
heightmap to UE4 with the other textures.
Am I restricted to use only 256x256 textures which would look terrible or how? Because rendering out a terrain with the detail of just 65536 vertices
in it would just look bad. And the textures too.

Basically I just want to have a small terrain with high amount of detail.

Hope for some advices

Sincerly ElGreco

Please any answer…

Import an 8k heightmap.

Scale it down.

Profit.