We did this trip our own in 2013. I combined the ABD and Tauck itineraries - ABD does GNP, Banff and Lake Louise, Tauck does Banff, Jasper and Lake Louise. I stayed in the park at GNP and Fairmont hotels in Banff, Jasper and Lake Louise. I did everything on both itineraries and then some. I spent around half of the listed price of the ABD at the time and our trip was 4 days longer. And, of course, there are meals and time on your own with ABD, as well as the guide's tips that aren't included in the listed price, so it was actually considerably less than half. I booked a rental car in Kallispell and had no issue taking it into Canada, but we did return to Kallispell to fly home. I'm not sure if I could have returned the car at the Calgary airport, but at the time, I think it was possible but just a lot more expensive. Not sure if it's allowed now. I booked both Lake McDonald and Many Glaciers at GNP about 8 months out. If you can't get a hotel within the park, hotels in Whitefish are a good option. It is nearby and it's a very nice little town. We loved this trip and were actually glad that we didn't do a tour for this one, because there is so much beautiful scenery and wildlife and we were able to stop whenever we saw something interesting. Also, we loved Jasper and it's not included in the ABD itinerary. The trip was super easy to plan and execute. It's was just me and my son, so I had to do all the driving, but it's an easy drive with no traffic to speak of.