Welcome to GOY. In the harsh winter we are experiencing it will probably just have shed its leaves. You could scrape the bark and see if under it is green or you can wait until everything else comes back to life and see if it does too. It is one of the hardiest plants I know and I would be surprised if it has died. It may have some die back at the tips but you can cut that away when it starts growing again. I would not touch it yet.

Agree with Scotsgran, although Escallonia isn't incredibly hardy, some varieties being only frost hardy. Wait till late spring, see what its doing then - in harsh winters, leaf loss is not unusual, but may sometimes mean the plant has been killed back to the base.

I think the same
It isnt the toughest shrub, but they do vary depending on variety, but it might be fine (i do hope so)
You would be best to sit it out until Spring and keep your fingers crossed( not sure that will help much lol)
Dropping leaves is a kind of securty measure, it makes it easy to look after the heart of the plant if you see what I mean.Lots of plants do that if they get a shock or distressed, and who wouldnt be in the weather we had!
Even though keeping fingers crossed doesnt help much I will keep them crossed for you, as it would be dreadful for you if it were to have died

I'm glad I found this question and answer, as we have had the same problem with our escallonia hedge this harsh winter (2010/11). Our hedge has always been evergreen with leaves during the winter, but now it's completely 'see-through' and bare, just like a deciduous plant.
It seems to have very tiny shoots appearing and it's green if we scrape the bark. So we're hopeful of a recovery to the thick hedge it once was.

You have a lovely secret garden there at the front it would be a real shame if you lost your hedge now. I would not cut anything away just yet as we can get severe frosts up until May and you need to keep a canopy above those precious shoots to allow them to come away again.