Van Rijn

“There are both pressure and temperature issues. At that pressure, there is a very narrow temperature range where liquid water can exist:”

As discussed earlier,

There is a big difference between air temperature and water temperature. For example, if a cup of pure water was placed in a room with the ambient air temperature of 100c the water in the cup would not boil till the temperature of the water in the cup was 100c at Earth slp.

I would think any water on a ground that was -65c on nightly bases would lengthen the window of the liquid state. There is no water temperature data and any correlation to ambient temp would be an uneducated guess.

Dfrank