I second the eye-mask and ear plugs suggestion--and I would bring a small supply of sleeping pills in case it's a noisy group. Bug spray, of course, and in case the nights are hot, a battery powered fan for the tent (ok, I'm giving away my age, that wonderful time of life when 40 below is still too hot at times)

A tiny travel alarm clock is helpful.

A great novel or two so you can have some down-time!