Data discrepancies could be down to where the station is located and website limitations etc. Also I don't think this year has been updated for Mt Buffalo's weather data. I would think Acacia phlebophylla has a good chance at lower temps and perhaps prolong cold temps as it snows every year at Mt Buffalo. I would say however it regularly snow/ gets colder further in land, further north and at lower altitudes.
For example Bathurst in NSW has had lows of -10c and Armidale further north gets lows of -11c - -12c. this is quite a few degrees cooler than Mt Buffalo despite 1000m elevation difference and the fact it is located further south. What I'm getting at is perhaps natives local to those areas could be more cold hardy than at Mt Buffalo. They would also likely be more heat hardy too. So Acacia floribunda (which i think is found in Armidale) could technically be more cold hardy than Mt Buffalo wattle? Worth an experiment.
It would not surprise me if there are a nice number of active acacia's that can handler colder temps. Keep in mind A. phleb is one of the few acacia's that can thrive and tolerate pots well.
For example Bathurst in NSW has had lows of -10c and Armidale further north gets lows of -11c - -12c. this is quite a few degrees cooler than Mt Buffalo despite 1000m elevation difference and the fact it is located further south. What I'm getting at is perhaps natives local to those areas could be more cold hardy than at Mt Buffalo. They would also likely be more heat hardy too. So Acacia floribunda (which i think is found in Armidale) could technically be more cold hardy than Mt Buffalo wattle? Worth an experiment.
It would not surprise me if there are a nice number of active acacia's that can handler colder temps. Keep in mind A. phleb is one of the few acacia's that can thrive and tolerate pots well.