I will echo that Marco's Argentinian species are more cold hardy than my other jabos, and flush out earlier, but again, I do not believe these to be revolutionary results. At best you're going to get +5f more temperature resistance is my guess.
You have folks like NissanVersa saying they lost massive mature jabos to 17f. So say you somehow had a lujan or campo with a 6" trunk - you'd lose it at 12f. You now mention you go below zero.
Sorry, but I think this is a rather foolish exercise and I don't get it. My jabos really suffer in 9b already.
Thanks again for the harsh reality check, K-Rimes! 😢