Ardour projects are self-contained by default, and can be moved between different systems and different operating systems.

The problem comes mostly from two angles:

1) DAWs which allow you to use external audio/MIDI files and do not place referenceable copies of them inside the session/project folder itself.

2) Plugins that are available on the original system but are not available for whatever reason on the new system.

In my experience, #2 is a vastly bigger issue than #1.