How to texture a large ground mesh? (not using unity's terrain)

i would like to know what the best practice is to texture a large ground mesh.
My goal is to achieve something similar like the ground here: Imgur: The magic of the Internet

Would the ground consist of 1 large mesh or be split up whever the texture changes?
Or is a style like in the screenshot realizable with a tilemap?

I think they (Gamefreak) solved this with a tilemap…