Eucalyptus Gunnii should be tough enough. I have a tree which everywinter faces several months of heavy frost and sometimes 6' of snow too.
In my spanish garden I have another which again gets some frost,last year -12 C degrees. The tree does suffer a little in the hot dry winds.

Here is a link that might be useful: Our Mediteeanean Garden

thanks for the response
I had an E.gunnii for two yrs or so but after a heavy frost it died back to earth.Here in northern Greece in the last 5-6 yrs it gets really chilly in the winter.
for example 2001 December -19 C.
2003 winter -17 C
2006 February -20 C
Also snow is prevalent here every winter.When it comes to the icy seberian winds...no comment.But I still try planting here subtropical species
I hope the 3 species I sowed are more promising.
thanks again
any other experiences?