I'm not familiar with WiringPi but I can tell you what I do in a similar situation. I create a stub module, that is a module that has the same classes, methods and constants as the module I need, but the classes and methods are empty. This stops my script from throwing errors related to an unavailable module and lets me debug the rest of my code.
For example, xbmc python modules are only available within xbmc, however you can uses stubs (like
this) to write scripts outside of xbmc.
The downside is that you obviously lose some of the key functionality that you want your scripts to have.
Don't know if this is relevant for WiringPi or not however I have used this for RPi.GPIO when I was testing a script on another machine and didn't want to comment out all the GPIO related lines.