The monorail is very easy access from OHana's. What you will run into is that most likely security will give you a large placecard to lay on your dashboard that allows 3 hours of Poly parking.
If you plan on a longer visit, I suggest parking at TTC, take the resort monorail to the Poly. The monorial is on the same floor as the Poly restaraunts.
After eating, ride the monorail to MK.
After MK, tale the monorial to the TTC.
Very easy over all and you don't have to be concerned about a parking time limit.
OHana's is very good food, and all you care to eat. It is very popular. Do not attempt to eat there without PS.