So.. no chance of temporarily putting other wheels of different material (re: wheelchair wheels, pneumatics?) on the bot for the day?
How about using a flatbed trailer to run the robot in and laying some carpet on it?
Then their is always the brilliant idea of trying to tow a section of carpet behind a truck and running it on that.. lol
I would actually like to see vid of the last one..

Anyone care to step up to that challenge?