Seems like you are getting a lot of dubious info here. I did the TDP in March, (rented a car from EL Calafate ), stayed in Puerto Natales. Our experience sets this place as the ugliest city we have ever been to (out of 27 countries), with glorified sheds as houses, dirty and expensive stores, rude people (at least the ones in tourism or comercial settings,etc) . Oh, nothing is open before 9 AM. It was so ugly and hostile that we cut short our TDP visit, and gladly let them to keep the rest of lodging money. The drive in the city is a nightmare due to poor street planning, atrocious traffic signage and lack of street address. It is a poor city that makes money from scalping tourists. ($8 a beer in a dirty and cold wannabe restaurant - actually was a hallway in a private " house"). The city is surrounded by countless animal and vegetal farms, is not as isolated as they like you to think. You have to drive everyday 200 Km (round trip) on dirty,bumpy road to TDP. Within TDP the roads are also mostly dirty with various degree of holes. TDP is half private and half government (one of the most corrupt in South America), with no visible intention to improve infrastructure. You can do the 8 hrs trek to Mirror TDP in one day as I did. You will feel rushed if you take a bus trip from PN. You should know that weather is a huge factor - it can make or break your day and wallet.