Winter Flowering Clematis

I love winter flowering plants, they make much more of an impact as an individual plant on a background of bare stems.
I planted  Clematis cirrhosa 'Freckles' about 4 years ago, on the fence surrounding the front garden, facing the driveway, so we can see the flowers as we go in and out of the house. Then came three hard winters and each winter there were one or two miserable flowers on the plant.
I started doubting the wisdom of planting it at all.

But this year, with the mild weather came a pleasant surprise.

The plant is covered in large beautiful flowers. I guess the weather does matter.