Flight from Buenos Aires to Ushuaia and then all the way back by bus. That means 4 hrs in the air and something between 70 and 80 hrs on the road. I stayed a few days in Ushuaia, Punta Arenas, Puerto Natales ( Torres del Paine ), El Calafate, El Chalten (Fitz Roy) and Puerto Madryn.
Three weeks are a short time to visit Patagonia. That means, there's no time to do extensive hiking in the mountains. Forget about double-u's and five day cirquits. Maybe you won't see the beautiful peaks because of rain exactly the day you spend on site and there's no time to stay another day. In fact, you can even spend five days in Chalten and never see the beautiful peaks of Fitz Roy and Cerro Torre. One mountaineer was already waiting 10 days for good weather to do a climb.
UshuaiaI was there between X-mas and New Year and there was no problem to find a hotel without reservation.
Buses to Punta Arenas leave at 07:30 in the morning every day. It is a nice 12 hours trip and you see quite a lot of Tierra del Fuego. It used to be a night trip with stopover in Rio Grande according to LP.
"Patagonia's most interesting and liveliest city" was just dead on New Years Eve.
Puerto NatalesI can't recommend Residencial Florída. No hot water, no heating, no breakfast just because I was the only guest.
Torres del Paine NationalparkPeople use to say Torres del Pay national park. If you travel without tent, sleeping bag and food, you will get everything...for a certain price.
A tip for "short-timers":Do the one day trip to the Torres del Paine national park . On the way back, get dropped at Guardería Laguna Amarga. Walk to the refugio Las Torres. Spend the night in the refugio. Get up early in the morning. Walk to the viewpoint of Torres del Paine. Walk back to Guardería Laguna Amarga from where you take the 04:00 pm bus which brings you back to Puerto Natales.
There are buses nearly every day leaving from Puerto Natales to El Calafate. Buses leave at nine in the morning and arrive in El Calafate early in the afternoon.
El CalafateThe only place where it was difficult to find a hotel. It was just after New Year and the place was packed with Porteños. There's not many low budget places in El Calafate. They were either complete or overpriced. I preferred to stay in Hotel Upsala for 40$ and have private bath, towels, central heating and a nice bed than paying 20$ for a bed in a shabby hospedaje. A good place to eat is a not very inviting no name restaurant between 1 de Mayo and the stairway to the bus station. It looks like a cheap cantina with TV and plastic chairs, but the food is surprisingly good.
El ChaltenA hikers El Dorado. Be prepared for rain. Don't expect to see the famous peaks and you will not be disappointed.
I left El Chalten at 06:00 am, spent 3 hrs in El Calafate, 3 hrs in Rio Gallegos and arrived in Puerto Madryn at 01:00 pm the other day. Maybe I should have taken the plane.
Puerto MadrynMadryn is a good base to do day trips to Peninsula Valdes and Punta Tombo. Unfortunately there's no wale watching season in January. It's not worth going to the Welsh towns like Gaiman. Having tea and cake for 12$ is a rip off.
The trip to Buenos Aires takes about 20hrs. All busses leave early in the afternoon.