Ummm..... Caerulea? Sunburst? Edulis? ...
All are maybe's as I'm not totally sure of their hardiness zone, but I've seen with my very own eyes caerulea survive 2' of snow & months of winter temps in the 30's.

It's planted right next to my Mom's place so may get some ground heat from the house, I don't know.

As for the others I've heard they can take 20's but don't quote me.

The native Passiflora Inacarnata and its hybribs (p.incarnata 'alba' and p.incense)are the most hardy(-12), also try P.caerula, P.caerula 'constance elliot' and
P.caerula x raxemosa (hardy to -8 so may need some protection) for best results plant against a warm south faceing wall in a sheltered spot. Sunburst and edulit are not hardy below -3.

I bought a passion flower from Lowe's last year. I work there. It said cold hardy to 10 degrees. Its purple. Didn't catch the name. But we got between 10 and 20 this year and lo and behold there it is coming up!!!