We know he wont remember this trip, but this trip is really for us and grandma, and a right of passage in our family. We are going to stay completely on his schedule (naps, eating etc.) and at a very slow pace
I'd say that judging by this part of your quote, you've already got the most important parts of a 1st trip with a young one mastered.
The trip will be for you guys more than him. We've taken both our girls when they were around 18 months, and they don't remember much typically. Just bits and pieces. You'll find out pretty early what he's up for and what he isn't. My oldest was down for just about everything she could get on at 18 months. My youngest ended up being terrified of all dark-rides at 18 months. You might be in a good spot though, because "fear" might not have really set in yet, so he might be up for whatever you are. Make memories, take pictures, meet characters, see parades and fireworks. Always know where and how the exits are though to anything you get in to, in case a meltdown requires a quick escape!
The second part you have right as well. Though this trip is more
for you, keeping to his schedule will make it more enjoyable for everyone. Getting naps in is key. We've kept both our girls up later than we typically would on a Disney vacation, and been very lucky so far. Both of our girls were enough off of their normal routine on their first trips that they basically refused to eat anything for the entire week. After a few days, we stopped worrying about it, let them eat whatever they would put in their mouths, and it removed a lot of stress (and they survived, I think my oldest ate nothing but cheerios and one box of Kraft Mac and Cheese in the room on our first trip with her).
For the plane, the only advice I'd have would be to allow enough time between the security gate and boarding to get the little one enough to drink on the plane. Whatever he's drinking, be it formula or milk. They need to keep drinking during take off and landing to keep their ears from plugging up, and we've had some bad flight attendants who would not get us something when we ran out just prior to landing (not during landing mind you, but prior to landing). Have enough so that he's got something to drink at all times.
Other than that, like I said, you're on the right track. You'll have a great time, and great memories. Then, you get to have another "1st" trip with him when he's a little older, the one he'll remember more of!
