Congrats! You guys are going to have a great time!
You guys may know this already, but thought I'd mention it.....
There was a law passed in Florida a few years back (don't ask me which Florida statue) that when you are at a theme park they HAVE to give you ice water at no charge. That doesn't mean bottled water. . . But any of the kiosks, restaurants, etc where they serve the fountain drinks will also give you a cup of ice water at NO charge.
You can still carry the bottle and refill it with the ice water they give you (which is usually better than the water in the fountains..yuck). I personally, don't like carrying around a bottle of water because it makes the backpack heavy.
Anyway, just my two cents.