Possible to extend terrain without changing the original?

[Alexx31]

Hello, is it possible to extend terrain with more tiles / partitions, but not to change the original existing terrain tile? (kind of a non-destructive extending)

This would allow extending a scene.
I saw some tutorials to create more additional tiles, but they do either only clone the first landscape (and maybe randomly rotate, but do not offer to work free)
or 
if they were strong modified also the first landscape is modified/altered.

Thanks