Cold in the teens/low 20s will zap the foliage. They will grow more in the spring, but if you can protect these leaves, it will add to the overall vigor of the plant. We can't grow this species here, but I have the same issues with certain other bulbs.

Best thing I know to do with plants like this is to put a deep layer of a light, fluffy, insulating mulch over them when the ground freezes (or when extreme cold threatens) -- pine straw, oak leaves, or regular straw is good. Then uncover when temps appear to be safe in early spring.

Now one of my precocious little bulbs has been coaxed out to bloom in the middle of winter, hopefully any freezes we have aren't too rough on them. Will cover with straw if cold weather persists.
I'll update in a week!

Matthew

Here is a link that might be useful: Anemone

I couldn't get a picture through your link.... just a login to flicker.

I'm a little jealous of your success so far, I think it's too cold here for their winter foliage to survive and planting them in the spring is just not enough for a real nice diplay.