Hi Sharon!
Pop Century at Walt Disney World in December brings back some great memories for me! I think you're going to enjoy Ohana's, too.
There are, sometimes, a character breakfast bus that runs early in the mornings to take guests from one resort to a theme park or in some cases another resort. I would recommend that you ask a cast member upon check in to see if the schedule/route matches up with your reservation.
It takes about 25 minutes of drive time to get from Pop Century to the Polynesian, but this time may be greater depending on various factors. If there is not a character breakfast bus available for you to take from Pop Century to the Polynesian (which I suspect may be the case since the ones I have noticed have been for earlier times), then you would need to catch the bus from Pop Century to the Magic Kingdom, and from there connect to the Polynesian by either monorail or boat. This could take anywhere from 40 minutes to an hour and 15 minutes. Factors that may influence the length of time include whether a bus is immediately available at your resort, or if you happen to have just missed the last bus and find yourself waiting for the next one, which may take up to 20 minutes. I would have my family at the bus loading area by 9:15 at the latest. If I preferred to be on my own schedule rather than on Disney buses schedule, and I didn't have my own vehicle, I would consider a taxi.
Hope this helps. Feel free to come back to the Moms Panel if you have more questions. Have a magical vacation!