1

Your itinerary looks fine but you are extremely late booking your flights and any lodging in Torres del Paine, which has very limited lodging on the cheaper end. El Chalten is small and also has a limited amount of places to stay. I would check the availability and cost of the flights first. Try both LAN (Punta Arenas) and SKY (Puerto Natales). Then check lodging possibilities in Torres del Paine and El Chalten.

2

You would make a better itinary changing the way you go to Ushuaia.
Go first to Ushuaia, then to El Calafate and El Chalten, from there to TDP and then to Punta Arenas again. Or go from El Calafate by plane to Ushuaia which is more expensive but much fsater than all these bus rides. From Ushuaia to El calafate by bus you can make it in one long day taking the early morning bus in ushuaia at around 6 o clock arriving at Rio gallegos at 6 pm and taking another bus to El calafate arriving late. It doesn´t work the other way as the bus to Ushuaia leaves Rio gallegos very early too and it makes no sense to stay overnight at Rio gallegos.
There is a cruise ship to Ushuaia from Punta Arenas, Mare Australis which is amazing if you don´t mind the money but it will cost you above USD 1500 for 3 or 4 days. There is a weekly ferry to Puerto Williams from Punta Arenas but it is difficult and very expensive to get from Williams to Ushuaia and this ferry does not stop or enter the channels with the best scenery.
For the refugios at TDP you should have already booked as said above. Flights can be tricky too. For El Chalten you should reserve in advance too. In El calafate and Ushuaia you will always find something but the best deals might be all booked. Punta Arenas can be sometimes tricky too, at least if you look for something cheap

Edited by: beerfree

3

You should do a I'd circuit of the area and go down to Ushuaia. Then swing up to el calafate and el Chalten. Then across to tdp. The timing is fine. It's just a bit crisscrossed.