Hi, Julie! Oh, sure! That plan is completely do-able. I popped over to the Magic Kingdom calendar and saw the scheduled hours for the park that day. (Of course, hours are subject to change.) Yet, the park is scheduled to open at 9 a.m. -- so if you arrive at park opening, you'll certainly be ready for your dinner break at 'Ohana by 5 p.m. Depending on where you are in the park, you need to allow for approximately 10-20 minutes to get to the front of the park and to the monorail station....go right once you exit the park. Make sure you take the
Resort Monorail (the station closest to the water), and the Polynesian is the third stop (Contemporary, Ticket & Transportation Center,
Polynesian , Grand Floridian, Magic Kingdom).
I'm guessing that you'll need to leave the park by 4:00 p.m. to allow for wait and travel times to the Polynesian...plus, if you're not staying at that resort, you'll definitely want to soak it in once you step off the monorail. Check in with the host/hostess at 'Ohana and ask for a table closest to the windows, if possible. Also, keep in mind that you may be attempting to leave the Magic Kingdom around parade time...so if you want to see the parade, just make sure you see it from Main Street or in front of City Hall or your commute to the park entrance may take longer than anticipated. (Tip: Many people make a mass exodus after the parade...so the monorail stations are busy!) Once you're done at 'Ohana, you'll have plenty of time to return to the Magic Kingdom and enjoy the park until closing. I hope this has helped you plan. Have a wonderful day and a magical vacation!