They should be able to join you rather easily. Although parking around the resort buildings is restricted to registered guests, visitor parking is available in the lot across highway A1A from the resort, with a connecting tunnel under the road for safe crossing of the highway. Visitors can simply drive in, since the guardhouse is on the resort side. They could call your cell and you coukd meet them in the lobby.
When Sonya's was still open, there were at least some local residents who dined there, so off-site guest accommodation has been a part of the resort for some time.