temperatures link
The links below appear to show that temperatures at 65 degrees latitude hover just above zero for 2 months or more. Add to this that dark soil will get hotter and salts can make water stay liquid down to 50 degrees below zero and the idea of water outflows is perhaps not so far fetched.
http://wwwflag.wr.usgs.gov/USGSFlag/Space/MGS_TES/
http://wwwflag.wr.usgs.gov/USGSFlag/Space/MGS_TES/spole99.html
The second link shows an orange graph of the temperatures at 65 degrees south. It appears that the temperature stays between 0 and 10 degrees celsius for about 2 months, or am I reading this wrong? It also seems as if the temperature varies about 5 degrees over a day.