Hi there, Laura!
It sounds like you have a fantastic evening planned by enjoying dinner at 'Ohana after spending your day at Magic Kingdom Park! Transportation over to Disney's Polynesian Resort will be a breeze for you and there are a couple of different options.
My first choice would be to ride a water taxi directly from the Magic Kingdom entrance over to the Polynesian. It's a nice little boat ride and I always love the view from the water. The other option is to hop aboard the monorail. You can catch the monorail right in front of the entrance to Magic Kingdom Park. I would allow about 30-45 minutes for either choice because even though they're very close proximity and won't take you long, you may have to wait for the transportation to arrive and you'll still need to walk to the restaurant once you arrive at the Resort.
I checked the calendar for that evening and I noticed that
Wishes nighttime spectacular is scheduled for 10:00 p.m. After dinner, might I suggest wandering out to the sandy shores past the swimming pool and pulling up a hammock for the fireworks? This could quite possibly be my very favorite pastime on the planet!
Thanks so much for stopping by the Moms Panel with your question, Laura! If there are any other questions you have, please feel free to ask!
Have a Pixie Dusted vacation!
~Jackie