Haven't taken a cab from POR to WL, but have done AKL to YC and ASMo to CSR. We just went down to the lobby entrance and valets either called a cab or flagged one for us (there are usually some waiting at the resorts). I believe they were Mears cabs. It cost less than $10-15 if I remember correctly. It was easy and quick. If room isn't ready, just leave bags with Bell Services to be moved once you have your room.