I have one near Albury NSW that has survived for 4 years so far. It has kept
going through at least a dozen -3 degree frosts, without any special
attention - although it is within a metre or so of a steel shed. One thing I
believe in with frost sensitive plants is to keep them well watered whenever
there is a possibility of frost. When I planted mine, it was only about 10cm
high and it is now over a metre though so far I have not had a good display
of flowers - but I am still hoping.
Regards
Phil.