We have driven over from Tampa to visit friends staying a resort before. I have not done this since 9/11/01 with all the new security, but I think as long as you alert the front desk and they show a picture id there should be no problem.
we were at wilderness lodge a few weeks ago, and my husband's family came and visited us. we told the front desk and they sent a message to the guard post and it was no problem letting them in.