When I did my 10 day trip from Nigel creek back through skyline to Jasper I originally parked my car in Jasper and took a bus down the icefields parkway. The driver was nice enough to stop at a pull-out about 2km from the nigel creek trailhead for me. So you could always try to get a bus ride closer if you don't want to hitch; having said that I did hitch back to my car a short distance and it wasn't hard at all as there are many cars.
How did you get from nigel pass to skyline? That would be an amazing trip!