I found these videos on YouTube. They tell the story of Britain's largest portable layout. It is OS2R and was built by Simon George. I wouldn't call it a modular layout because it wasn't built by multiple individuals and the modules only go together one way. It does show, however, that OS2R can be well done in a portable layout. The layout is moved to train shows and events around Britain and showcases OS2R at its best.
This is the type of exposure that OS2R needs in the US. Hopefully, OSC modular standards will enable US OS2R modelers to build a similar impressive display at our train shows. I think that long reefer trains pulled by a Big Boy or Cab Forward will jump start interest in OS2R. NH Joe
Here is how the layout is moved.
Here is another video of the display. The text gives a better story about the layout.