Be prepared for the worse, be expected for 100 or even 1000 people to show, even though it might not happen. Be prepared! Run your lines to the point to where they are drilled into your brain and most of all stay calm. You definitely do not want to have a panic attack while your giving your speech. Find a familiar face in the crowd and focus on them, if there are none, imagine everyone naked. Be energetic and do not drone on, make it exciting.
Good luck