Developing for other platforms/ consoles

Hi, I have a game made for PC and if I were to port the game to switch or xbox, is it best to duplicate the whole project or just do some adjustments in my current project?

I am hoping that duplicating the project will not be the best choice since my game is a big project.

thanks

 

I believe the right idea would be to make adjustments to current project so it compiles correctly for all targets. For platform specific stuff you can use conditional compilation.
https://docs.unity3d.com/Manual/PlatformDependentCompilation.html

You should not duplicate, because the versions will very quickly desync.