Anybody that connects a mic through 100m of cable is a fool looking for trouble, or a desperate man.
I know plenty of live venue's where the cable run from the stageboxes to the controlroom exeed 100m lenght.
Actually, I think this goes for most large venue's.
You could place your mixer first row and sit with the VIPS and use short cable runs... but I don't think that would be much appreciated.
Now if you are really looking for trouble, try to set up 40 wireless connections in a city like Amsterdam