Throw a Stick of Sage into the Firepit/Bonfire. The sage scented smoke that the fire will emit keeps mosquitos and other annoying bugs at bay for the entire area. Usually the sage stick is enough, no need for bug sprays.
Empty a dozen eggs into a mason jar for easy travel. They fit perfect in the cooler without the worry of breaking. Just pour them out as you need. I would want to use a plastic mayonnaise jar so I don't worry about breaking glass.
Mentholatum ointment (or Vicks) repel mosquitoes more safely than DEET. This is one I will try, especially around the ankles where the mosquitoes always seem to attack. (Definitely worth a try since I'm a mosquito magnet.