My biggest dream has always been to travel all the way from Buenos Aires to Tierra del Fuego and then up to Santiago... by car.
I have about 5 weeks to do this and ideally I would like to include Peninsula Valdes, Ushuaia, Torres del Paine, El Calafate, El Chalten, the area around Bariloche and then cross into Chile and visit the area around Puerto Montt, Chiloe and then up to Santiago/Valparaiso.
As I know I can't pick up a rental car in Buenos Aires and leave it in Santiago, I was thinking of flying to Bariloche (from BsAs) and then drive to Peninsula Valdes etc... and return to Bariloche from El Chalten to return the car and go (by bus?) to Puerto Montt. There I would rent a car to visit the area and Chiloe and go to Santiago by bus.
Is this a good idea or is there a better way to go about doing it?
Any idea if all of this is doable in 5 weeks?
I am from Chile, but I grew up in Chile and Argentina. Hence, I can give you some advices. I have been several times in Patagonia. It is great!!!!
First at all, you must travel during summer time (December to February), otherwise, it will be very rainy in the southern part of Chile.
As you known, you can not rent a car in Chile and drive in Argentina. Then, you must plan you trip thinking to cross the border by plane or bus.
To visit Argentina, I recommend flying from Buenos Aires to Bariloche (nothing interesting between BA and Bariloche), and then you rent a car in Bariloche and drive south. Once you travel in Argentina, you can go to Chile by bus. (only 5 hours trip from Bariloche to Osorno).
To visit Chile, you should rent a car in Osorno o Puerto Montt. You can also fly from Puerto Montt to Coyhaique and rent a car there.
5 weeks it is not enough time for the travelling your are planning. Distance between cities is the main problem.