Passiflora

It is now a couple of years that every spring/summer there is a passiflora plant on our balcony. Unfortunately, though, for a reason or another, it dies.
Once, it died because when we were away during summer it didn't get enough water.
Another time, during the winter period, it got too much water, another time too little. Another time I don't know what happened.

The thing is, it is one of my favorite plants and when it is late summer it blooms wonderfully in our balcony! So, it has to survive the winter and come back the year after!

The plant is having a great summer/autumn in the balcony since it is exposed on south-west and that is the ideal place where it should be. It wants a lot of sun and I have placed it near the window, able to climb on the wall, and there, even though I close a bit the curtains, it can get a lot of sun.

During spring/summer, it needs a lot of water. I water it every day or every second day, depending on how warm it is in our balcony (which is closed by glass). When I see some yellow leaf starting to appear, it is sign that maybe I have been watering it too little. The terrain should be wet but not too much or the roots will rotten. When it is dry I just add plenty of water to the vase.

The typical way of blooming of the plant at its second or third occasion (autumn bloom)

So, what is the problem? When winter starts, the aerial part of the plant dries out slowly slowly. That is supposed to be ok. It is time then to prune the plant and let it rest for the winter, covering the roots so that they don't get too cold.
The plant can experience quite cold temperature: they survive, although they are tropical species, even around -10 degrees. I even managed to have it ok last November, when outside it was -20 and the glass of the balcony was protecting the plant.

I haven't yet managed to have the roots in good state at the beginning of the spring, so this is this year challenge: to have the plant surviving and coming back next year.
Will I manage? I welcome any suggestion!