I'd say you'll have 60-90 min to leave MK, boat to Poly (my advice vs. monorail with it's several stops), eat and boat back.
Nice tidbit, time it around dusk and you can catch the torch lighting ceremony at the Poly (very fun)
Cool! If we could afford it, that's probably where I would have chosen to stay. I don't know that we could ever afford it though.

Looks like sunset will be at about 7:50 p.m. on the day we're there- so odds are we will probably miss it. The park is only open until 9:00 p.m., and we want to see the fireworks and get the most out of our day. An hour to an hour and a half isn't terrible though, if it includes transit and dining. I will keep it on the short list! I can only imagine how cranky this day of endless heat and walking and transit will make him though....I really have no idea what to expect out of this! Thanks again for sharing your wisdom!