Patty,
I went to Mount Panorama over Chrismas ( see www.panoramaresort.com and getting here for the airports you might be referring to ) and looked at various possible connections to the area but there did not appear to be too may subload options ( granted I was coming in from the UK ) so I opted for Calgary ( YYC ). Most of the usual rental car suspects are available there. Depending upon where in the park you are going it is about a 3 hour drive however once you get into the mountains of the Banff National Park it is a stunning drive.
Paul