is there a way to separate a mesh and its texture?

i have a big mesh of El Capitan mountain (about 100,000 polys, its has a lot of surface detail) and a big texture (16x*16x). i want to split it into manageable size segments to use in unity, so maybe 4x4 tiles.

i think i can split the mesh easy enough with the ‘P’ key to separate right? but what about the texture? is there any way to automatically split the texture into matching tiles that perfect fit the new split mesh segments, so that the edge between adjacent meshes looks seamless?

thx steve

i was looking at texture painting with clone brush but all the examples i’ve seen are panting on a single object. if i split my big mesh into say 16 tiles, is there a way to create a new texture for each tile (object) then paint all 16 connected objects from a since super hi res source image?

pls help someone, i’m not good with blender