You can stay on-site, at Keuka College.
They make a field and parking lot available beside the athletics building, and allow access to the showers, etc. There aren't electric or water hook ups though as it is not actually a campground. But you can't get any closer, and the price is right, $8/person/night.
Here's the blurb from the event program handout.
Camping
A location on the Keuka College campus is available for tents or for fully contained camping vehicles. There are no electrical hook-ups or sewage disposal. Portable toilets will be on site, and Davis Hall, which is near the camping area, will be available for bathrooms and showers.
The campus camping fee is $8/adult (16 and older) per night.
Keuka Lake State Park is located on the lakeshore 1 mile south of Keuka College on Rt. 54A. The park has tent/trailer sites with hookups, showers, dumping stations, a swimming beach, and hiking trails. For reservations call: 315-536-3666.