I've only chaperoned a few times, but I've always gotten a group of kids to chaperone. My ds generally does better in public than at home, so he's been okay. Generally the only problem for the chaperones is that ds walks so slowwww. He's gotten better over the years.
Ds actually had an overnight field trip (at a nature center) this past Mon/Tues. I couldn't chaperone overnight, but I went as an aide during the day. I saw ds at mealtimes. He did GREAT. He said it was his best field trip ever! He even took a shower when the other boys did even tho' it was off-schedule for him.
I *have* noticed that ds is usually paired with a group of respectful kids. That probably helps ds function better and enjoy his trips more.