FYI, there is a good chance you will not be allowed to park at Polynesian without a dining or resort reservation. You may be directed to park at TTC & have to walk or monorail over. All monorail & Epcot resorts have gotten very strict with parking. It may depend on the guard on duty & how busy the resort is. If you’re going to be there after mid July, I expect them to be very strict because of the nighttime parade.
Edit to add: since you’re staying on property, better to use Disney transportation. You can bus to MK & monorail or boat to Poly. Or go to a park & take a bus directly to Poly. Reverse to get back to your hotel, or ride share. Minnie vans would also be an option & they can drop at the resort while a ride share may be turned away.