Maybe this will help you to make a decision:
I have just came back from a 3-week trip to Bolivia visiting my in-laws in La Paz. I spent 6 days in the Condoriri base camp, from Aug. 11 to Aug. 16, and climbed the direct face of Peq. Alpamayo as a warm-up, then "Normal" (non-face, as face is all rock) route on Cabeza, and finally the "British route" on Huallomen. The first two routes had perfect neve on them, the third one, usually a mixed ice climb, had rather little ice, requiring more rock protection and rock-climbing than usual. This season, according to local guides, is considered rather dry.
On the last day we got dumped by a foot of snow. Generally, weather in Bolivia is very stable, however in August there is a chance of snowstorm, usually closer to the end of the month. The snowstorm of 16-th was considered by local an anomaly. Before the storm, the pattern was to have clearing during the night, good weather until 1pm, then fog/clouds rolling over, maybe with some little precipitation between 3pm and 6pm, then picking up winds and clearing through the night.
On political situation: nothing indicating instability similar to 2004/2005 is happening at the moment, so this would not be your worry.