I don't go by average winter temperatures, or average lows either, when mentioning species as being from the Temperate Zone. You see, there are different definitions. Some climatologists claim that Washington,D.C., is Sub-Tropical; others say, that, in the eastern United States, the southern edge of the Temperate Zone has been, at least until the last decade, near Cape Canaveral, Florida. I hold with the latter.
If there is a freeze ( a few minutes at 0 C / 32 F) some years, but not other years, that sounds Sub-Tropical to me. If there is a freeze every year, I believe it to be Temperate Zone.
In southern Brazil, all of Uruguay, and well down into Argentina, there are several Annonaceae, including edible-fruited Rollinia species (Annona if you prefer), that survive and prosper through annual freezes in the low 20's F. Same goes for several genera growing several-100 kilometers north of the southern border of China.
Some of the Cerrado-scrubland Annonaceae from the central plateau of Brazil, were probably in mild Temperate Zone during the last ice age. Annona coriacea, "leather-leafed sop", can survive several hours at 25-degrees F. without damage even to the leaves.