Everyone must be off both the Magic and Wonder by 9:00 am on debarkation day. They need to get the ship ready for the next sailing in a few hours so they want everyone out of their cabin by 8:00 am and off the ship by 9:00 am.
Is PC Pop Century resort??? Can't say how long lines will be to check in there...it's a holiday weekend so it may be crowded or the date of the 4th might actually be better f or checking in since most people may have already started their vacation earlier.
It should only take you a few minutes to gather your luggage at the port and go through customs...the ride to WDW is about an hour or so.
I would say you could be at the MK by 11:30.
MJ