No not too late, I generally do mine about this time - it's just it won't make any new growth until the warmer weather.
Once it gets going again, start tip pruning to make it branch out more, as it flowers on the new growth and you'll get a better show next time.

Thanks very much Alison, I will try it and I'm glad you mentioned about not making any new growth, as probably otherwise I would have worried that I killed it....