We only did it once and that's when we were buying into DVC. Our guide got us an extra night on points at OKW (to add to our already stayed 8 nights) and we didn't have to move.
That being said, I'd make sure it was on both reservations, DVC and CRO. Then once you get there, make sure they are aware AGAIN.
Oh - I just remembered. We had a one bedroom at SSR once for a couple of days and then needed a 2 bedroom for the last 2 nights. It was all DVC points, but we noted on the reservation that we really preferred not to move, esp since it was a change over Thanksgiving. We got there and talked to the manager on the first day just to make sure they knew and see if it was possible. She said the rooms had already been assigned, but the room assignor must have missed the request. She thought it would be stupid for us to move and create more work for housekeeping as well at a busy time. So, she manually fixed it so we didn't have to move. Her only thing was that we couldn't get our keys for the 2nd bedroom until after 11 am, even if the guests left way earlier. We said no problem - that our guests weren't even arriving until late that evening on that day. So, it worked out well for them and us.
My one suggestion would be to make sure BOTH the DVC ressie and the CRO ressie are in the same name (ie, not one in husband, one if wife). The room assignor is more likely to catch it then (I think that's why they missed our ressie above - because the one bedroom was in my name and the 2 in my hubby's).
LOL
