The comments are suggesting that this is niche. I don't think it's niche at all. On products I've worked on, I've frequently declared that all usability testing should be done when you're exhausted and grumpy. You don't tolerate

    * pointless process,
    * extraneous fields,
    * improperly labeled things,
    * poor ordering,
    * sloppy UX flow,
    * excessively accurate controls, 
    * super-tiny buttons, 
    * things when you're like that.

In a similar way, when you're drunk, you can't /do/ process like that.

I think it's a lovely idea and more systems should be designed with that in mind.

Drunk, I might be able to operate a computer as well as my grandmother; so, if it can support me drunk, it can support my grandmother.