You are indeed on the right track!
Since you are going for the three dimensional feel you can create multiple landscapes as different levels using ‘World Composition’ and stream your levels in and/or out within the screen space.
Check out the documentation on ‘World Composition’ to see how it can be used. This will allow you to save processes for other things in your game so you aren’t rendering an entire world at runtime.
World Composition
Even though this is one way to do what you are trying, the most optimized way would be to have all the static meshes and modular pieces procedurally generate across the screen. This way nothing is rendered out of the screen space at any point to optimize your games performance.
I hope this helped get you a bit further on your way. Keep me update as to how this is going, would love to see progress.
Thanks,