Just a small note I forgot to add...My plants are still outside on the deck and our temps have dropped to 4 Celcius over night with frost already. It took out my moonflower and heliotrope but the vines are both still doing okay, flowering stopped a few weeks ago but the mandevilla is still blooming. Makes me hope!

I have no idea what varieties might be hardy in your zone, though no passiflora can be above ground in a pot over the winter where you have below freezing temps. Some varieties if planted in the ground will come back from the roots. I cut my container vines way back and grow them like houseplants over the winter, either in a heated greenhouse or in my house. They look pretty shabby by the end of November but they come back when they go back outside in the spring.
Karyn