Puerto Madryn isn't the attraction, and it knows it. It's a wind-scoured port of about 103,000 people on the Golfo Nuevo, and it exists because of Welsh settlers. On 28 July 1865, 153 of them came ashore from the clipper Mimosa, found no fresh water and walked on to the Chubut river valley. The town grew later, when a railway inland to that valley was started in 1886. What makes it worth the flight now is what lives within a few hours' drive: southern right whales, Magellanic penguins, sea lions and elephant seals, and the UNESCO-listed Península Valdés, which keeps most of them in one place.
November is a good month to be here, and an unusual one. Right whales are in the gulf from June to December, and the boats at Puerto Pirámides sell their high-season tickets until 15 December. The penguins are back too: Punta Tombo opened for the season on 14 September, and its own advice is that October and November are the best months, with chicks hatching. Orcas are not part of this trip, because the famous beach hunting happens in March and April. Three days fits the geography: one for the town and the whales you can watch from shore, one for the peninsula, one for the long drive south to the penguins, with Welsh tea and dinosaurs on the way back. Two of the three days are long drives. That's the honest price.
The plan runs by distance: day one stays near town, day two covers the peninsula, day three goes to Punta Tombo, Gaiman and Trelew. The big sights are open every day, so the start weekday matters less than the wind: whale boats stop and gravel roads close when it blows, so keep the two long days swappable. Gaiman's tea houses keep their own days, so ask. More on the country is on the Argentina page, and our Buenos Aires guide covers the other end of the trip.