If you are concerned at all about changing him (diaper style) you may want to bring a waterproof picnic blanket that rolls up. Yes, it is much bigger than a changing pad, but if you need him to lay down for any reason, it is on this and it is washable along with not that bulky. You did say you would have a stroller too. Remember there are family bathrooms too. I would recommend that one person goes, you try the family motto everyone goes! This may help him since everyone is saying we all have to try! Good luck. You will have a blast.