A little more specific on the DVC villas at WL - Copper Creek studios and one bedrooms only sleep four. You'd need a two bedroom or three bedroom or Cabin there with five. Boulder Ridge studios sleep five, but one of the beds is a bunk sized murphy bed ( it is smaller than a twin sized bed - shorter and narrower). One bedrooms at BRV sleep four (one two beds - one king bed, one queen sleeper sofa).
But, if you book a hotel room, you'll pay extra for each adult (18 or older) more than two in the hotel room. You won't have to pay for extra adults in villas through DVC, but not sure if you book through Disney Reservation Center.