I couldn't help but be attracted to this post since my wife is from China. Upon asking her and Googling XinJiang, I now understand that the province is mostly zone 6, and it is very dry. The 40 N latitude band slices XinJiang in half north to south, so perhaps those figs are hardy to zone 6?
Do you know anything more about this fig tree? Would you ever plant this in the ground?
Also, what zone are you in? Rather, where are you?