I don't think is a very cold region variety. At least from what can be read about the variety in french sites (beware that some mistake it with Sultane):
Information on a french website - the author of the text considers it it's second best of 2015 summer:
http://acclimatons.com/mon-palmares-des-meilleures-figues-de-lete-2015/
Google translation
Google translation from this french website: - http://www.fruitiers-rares.info/articles75a80/article76-culture-Figuier-Ficus-carica.html
"A few years ago, I had to part from a plot of land containing a beautiful fig tree of great interest. It was an individual of the unified variety 'Bellone', aged 17 years and driven in tuft. I had initially planted five fairly high cuttings (between 0.5 and 0.8 m) arranged in a circle and slightly inclined. I voluntarily let them grow without any size. The result was a 3.5 meter tall tuft with five trunks and long lateral jets, some near the ground, giving it a wingspan of six meters. The variety 'Bellone', formerly known and practiced in the area of Nice is one of the varieties of fig that I prefer: its fruit has an exceptional character. The color, texture and taste of this fig combine both the refinement of a first-rate cultivar and the characteristic and surprising features of a wild fig tree. Who never tasted a very ripe Bellone fig will never really know what a fig is ... Contrary to what is often written in the literature, this variety produces rather large fruits (provided, of course, not to be planted in a field unfavorable to the fig tree). In addition to its extraordinary organoleptic qualities, this variety lends itself wonderfully to processing (drying, jam, compote ...)."
Variety photos
The french description in Baud's book.

It does seem a very rare and precious variety. I hope that the single cutting i received survives.