GoatPhD

Beginning planning a trip next winter down to patagonia to Fitz Roy and Paine. Does anyone have experience/beta on the SPIF, specifically the route from Lago Electrica/Paso Marconi to Paso de los vientos? How was the access up to the pass to get onto the ice field. Any info on permits, etc with the 'international border crossing'? We are not looking for a guide service, but there seem to be a lot of those too. Also, preferences for conditions (particularly the winds and stability) in late December/early Jan versus Feb/March? If the weather is good and we get to use our extra days at Cirque of the Altares, are there suggested routes/explorations?