If you are caught driving with only a photocopy of your license, you will receive a ticket for driving unlicensed. You will need to go to court and show the judge your valid license in order to get the charge reduced to driving without possession of license, which is less serious and usually just a small fine. I don't think that such a charge will delay your exit from the country, but if you fail to take care of it (or hire a lawyer to do so) then it may complicate your re-entry.

With that said, the chances of getting caught are small, but remember that it is possible to be involved in an accident that is completely someone else's fault no matter how well you drive. It is up to you if you want to take the risk.