Hi Mark,
Disney transportation typically runs for an hour after a park closes and that includes the monorail, buses, and boats. Sometimes they run a bit later, but the official time given is one hour. The good news for you is the monorail usually runs until an hour after the Magic Kingdom Park and Epcot both close. Since Epcot will not close until at least 9 pm, you should have plenty of time to catch the monorail back to the Magic Kingdom Park where you can take the boat back to
Disney's Wilderness Lodge.
That plan depends on the boat to Wilderness Lodge still running when you are done with your dinner at Kona Cafe. You might want to check with the lobby concierge to see if they can tell you if the boats are still running before you get on the monorail.
If your dinner runs long, or you decide to get a drink at the Tambu Lounge before you leave, you might have to get creative. You can always take a bus to a park that is open and transfer to a bus to Wilderness Lodge. You could do the same thing with buses to and from Downtown Disney. The bus is free but it can take a significant amount of time. You can also take a taxi back to your resort. The distance from
Disney's Polynesian Village Resort to Disney's Wilderness Lodge is not very far and shouldn't cost too much. It might be money well spent at the end of a long day.
Thanks for stopping by the Disney Parks Moms Panel!
Wishing you a magical vacation,
Amy H