I just received an email from John, the DEWNR area manager in the Lake George district. He reports that the last water level from the Big Lake on Dec 22 was 0.117m ADH.
Looking at he historical records, that appears to be similar to, or slightly higher then, the levels in the years 2012 and 2013 at the same time, when the season levels were excellent for us.
Historical plots suggest that the levels in the Big lake seem to be comparable with the Middle lake, at least for this time of the year. (Middle lake on left)

From memory, I think the best levels for us in the middle lake in 2012 and 2013 were around -0.5m or perhaps slightly lower..
This suggests to me that, unless we get a lot of water inflow in the next month, and we get normal summer evaporation rates, water levels will be similar to, or slightly higher than those of 2012 and 2013 in Jan/Feb 2018.
John said that the Big Lake station has a water level sensor that is working but the logger is broken so we cant get live updates at the moment. The best they can do is manual readings. and he will try to get an update of the current level and see if they can get regular manual updates over the next couple of months.