I have read many things about these 2 vines. I am interested in trying to grow these species, but only if it is at least marginally hardy. But hardiness reports do not always converge. Some say the low twenties (22°F-24°F) others 28°F-30°F. What should I really expect ? I know frost hardiness is not an exact science, but I'm sure the estimation can be more accurate than that.
Any insight ?

GingerSt 

(-5°C/1°C, 25°F/35°F

i keep them in a botanical cold glasshouse , this winter in northern france is long and hard , i keep them alive with an electric heater over frost , no problem this day , some leaves closed to the glass have frozen but the creeper is alive ...

http://gardenbreizh.org/photos/bebechat/photo-297440.html