sectial,
Can you provide any additional specifics and feedback that we might be able to use to help improve your plans?
For example:
Can your disabled friend drive a car?
Are you flying on Sunday?
Are you staying in a hotel in Atlanta (and could you change that to a hotel near/in Gatlinburg)?
Can your flight plans be changed (perhaps you could fly to Knoxville where the drive to Gatlinburg would be shorter)?