That depends on the variety. Do you know what it is?

There are very few Passifloras that will survive z6 winters.
Why not bring it indoors? You'd be surprised how well Passionvines adapt..set in the sunniest window..a cool room won't harm do it harm...
It's advisable to cut passionvine back in February. When I had mine, (before it froze outdoors) it grew up the wall, and across the ceiling..Depending on the variety, they can bloom as early as Apr. Toni

It does say now that it can thrive as a houseplant...but I know from experience the first thing that tropicals do in my house when brought indoors is make a huge mess with their leaves. Of course this one did nothing all summer and now it is all budded up. What about repotting? When is a good time? This one does look rootbound

I wouldn't repot until the spring. Use a grow light of some sort while it's inside and keep the humidity up. I'd make sure it gets about 14 hours of light per day. It will still drop foliage once you bring it in but the grow light and daily misting should help. If it holds it's buds you can always cut it back after you get to enjoy some blooms. That will make it easier to care for over the winter.