If you book through CRO (and your
travel agent) you will not be able to book five people in a one bedroom villa. CRO will not allow five in a one bedroom. There is only sleeping space for four anyway.
If you rent points from a DVC member, you might be able to fit five people in the one bedroom, but you would have to bring your own sleeping materials (aerobed, whatever) for the fifth person and you would only have towels for four.
The Contemporary or Polynesian are both very nice resorts that sleep five very easily. We had five in our Polynesian room on our first trip before we bought our DVC points. Two queen sized beds and a day bed. We stayed in the Contemporary Resort this past summer and it also had two queen beds and a nice sized day bed. GF rooms seemed smaller than either the CR or the PR.