My thoughts would be to wait a few weeks,and see if there are any signs of life,when it comes warmer,and then think about pruning it back.The more experienced gardeners on here,are sure to give you the correct advice,as I could be totally wrong..good luck.

They will do - mine does! Don't worry - wait a short while, maybe at the end of February/ beginning of March, and cut it hard back to the buds growing that you should see about a foot or a bit more up on each stem.

Did you cut it half-back in the autumn? I do that normally, to avoid windrock and possible damage from snow.