Advice on mainstream residential trip please

My 10 year old is in Y6 in mainstream school and the Y5 & Y6 classes are due to go on a residential trip this year. I would love for him to go as he will get loads out of it - he has seen a film of where they are going and what they will be doing. He has never managed a sleepover (even with his cousins at Grandma & Grandad's house with me downstairs) because he gets incredibly hyped up - every time we've tried it, with a social story about sleepovers in advance, we have had to abandon it, which leaves him feeling like a failure. He doesn't get invited to friends' houses, even for tea/to play, so I can't really do any practise runs either. 

I've tried to get across to school how unsettled/anxious/hyper/stressed he will potentially be and how it will spoil the subsequent days for everyone if he is running on empty due to a lack of sleep but they just say that we'll talk about it further down the line. I feel they think I'm being neurotic about it but bedtime really is a finely tuned process in our house otherwise he will be like the energiser bunny for hours and hours.

It's a really expensive trip, £230, and the non-refundable deposit is due next week. My issue is that school won't discuss with us any details on how they will manage him during the evening/overnight and with his daily hygiene (we have to make sure he has washed, brushed his teeth, changed his clothes or he won't do it) - they want to leave it until nearer the time. However, if the plan isn't satisfactory, I would have to pull him from the trip. I have offered to go along as a parent helper but they aren't ready to arrange that yet either and I think they would prefer me not to be there. Unprompted, our son has said that he won't go if I don't go with them which would be a real shame. I fully appreciate that they want to develop his independence but this is a giant leap for a 10-year old, who is emotionally closer to a 7-year old, and I feel that we haven't got to a point where we all understand what his needs will be, how to manage them etc- certainly not for me to stake money on anyway. 

I'm thinking of giving them a rundown/list of all the potential challenges/his routines/rituals so that they can come up with a plan for them or whether they want me to go along. Any other thoughts/ideas?