My DS9 is also in sixth grade. This is a hard question; in making the decision I'd (or I will, when the time comes) consider his level of maturity, how big a deal it would be to skip the trip, how he relates to the other kids, how they relate to him, and maybe how helpful the teachers and other parents can be. Meaning, if you can go for one night and your wife can go for one night, can you ask a couple parents that you trust to keep a little bit of an extra eye on him?
Overnight trips haven't come up for him yet, but FWIW, he went on an all-day field trip with a group of kids aged 11-18 on Friday. He had a great time. He seems to get on well with them and managed to get into what I would describe as age-appropriate trouble. It had something to do with a can of soda spraying out at a fuel station. The other students involved were 11 and 14.
Hope that helps.
Val
