No matter where you camp, everyone has to walk along Suttle Road to Aero Road and then walk half a mile on the Fair property to the admissions booth.
You may want to make sure that any information a campground publishes about how far they are from the the Fair INCLUDES the walk from Suttle Road to the admissions booth.
From GnomeWood your total walk is 8/10th of a mile (eight blocks) and takes 15 minutes at an average pace. You will walk 1/3 mile to Aero Road, and then a half-mile path through forest and fields takes you to the gates. If you have little ones in tow, you'll want to seriously consider bringing a wagon or stroller.