Bus to El Chatlen, Refugio Los Troncos

Hi all,

A couple of random questions in preparation of our trip to Argentina in a couple of weeks:

1) We fly from BA to El Calafate with a scheduled arrival time of 1605h. Barring any delays, is it possible to make it from the airport at El Calafate to the bus terminal to catch the 1800h bus to El Chalten?

2) We are planning to hike around Mount Fitz Roy and were thinking of staying at the Refugios Los Troncos (mid-December) for one night. We are planning at staying at refugios' the entire time we are hiking within Patagonia to lighten our load by not having to carry sleeping bags, tents, etc. I know Los Troncos doesn't accept reservations, but what are the chances that they will be full?

Thanks kindly!
Mel