the rooms at WL are smaller than the larger deluxes the only way i can imagine them fitting 5 is if you have bunk beds and a pack and play crib? even if they let you it'd be a tight squeeze!
The only hotels that I know for sure can fit five in a room is CR, Poly, and GF (that's regular sized rooms not suites). They have 2 queens and a twin sized daybed.
If you have more than 2 people 18 or over in the room then there is an additional per night charge per extra adult. It apparently varies from resort to resort; 15 for moderates and 25 for deluxe.
hope that helps!
geek