Hello, Hope,
I'm sorry to say, but the maximum capacity is for 5 guests; they won't be able to make any exceptions. However, you are welcome to visit the resort to dine and to shop or even to watch the fireworks from the beach.
I'm not sure what time of year you are traveling, but the rates for the Polynesian Resort are lower in off-seasons, and you may be able to find a
Special Offer to make it possible to have 2 adjoining rooms. I realize that still doubles your cost, but I wanted to make sure and let you know of this possibility.
With a party of 6, have you looked at the the
Cabins at Fort Wilderness? These cabins are made for up to 6 guests. Similarly, the family suites art
Disney's Art of Animation and
All-Star Music resorts can also accommodate up to 6 guests.
Wish I could have had better news, but you are still going to Walt Disney World!