That sounds like a good long trip to me - but even then, one must accept that it is impossible to see and do everything. You know he saying about planning and laughing, I'm sure.
Arrival day sounds like a very long day, with an early flight, and IMO, you might end up with cranky pants folks on your hands if you push to do too much that first day.
I think if you make a list of things that are absolutely "must-do" things, and can take a few deep breaths and realize the rest is gravy, everything will go great. There's a spreadsheet in my PTR linked in my signature if you want to see how I've done it. There are always trade-offs, but I'm generally at peace with my 11,374th spreadsheet revision. LOL
You are right on all accounts. And the reason this trip is longer is because all other trips we were exhausted from doing too much over too little of a time period and then didn't make time to enjoy the resort. Resort days are important to us and I need to remember this. Thank you. My husband and I will have two high school seniors (18 and 17), so this is not about doing and seeing it all, but letting them have fun and remember what it is like to be a kids before they graduate. Thanks again for your advice!