apparently Bariloche has a variety of micro-climates some milder near lake nahuel huapi and some at higher elevations away from the lake colder. the big eucalyptus you saw (maybe eucalyptus globulus---not generally recommended outside the mildest areas here in Oregon but the hardier and closely related e. nitens grows to similar size and look and might be worth a try) may well have been in one of the milder parts? good luck.