Although time can be very little and more expensive than being 3 days we tell all our customers that if they can. You can visit Torres del Paine in 2 days and 1 night or a weekend.
Here's how you can do it.
You should arrive on one of the first flights to Punta Arenas, it is recommended to leave from Santiago on the Flight from 05:00 - 05:30 am. To get to Punta Arenas around 09:00 am. Lan Chile Has good hours for this purpose.
Once in Punta Arenas you should Rent a car (You must do it in advance) and leave for Puerto Natales, which is about 3.5 hours away, we recommend having a light lunch and continue to Torres del Paine which is a 2 hour trip.
Visit Torres del Paine National Park and go back to sleep at the hotel in Puerto Natales.
The alternative that we recommend in Torres del Paine (by car) is to enter through the entrance of the administrative headquarters, visit the beach of the ice in the Hotel Gray, cross the entire Torres del Paine National Park and exit the Laguna Amarga
Return to Puerto Natales and accommodation
Planning the return to Punta Arenas (+ - 3.5 hours from Puerto Natales)
Departing from Puerto Natales to visit the famous Milodon Cave (25 km from Puerto Natales), the visit lasts approximately 1 hour.
Return to Punta Arenas to take the flight to Santiago.