I had a similar winter and have a similar problem. Today I was out breaking branches looking for signs of life.

I have chosen to wait and see partually because I have no replacement picked out.

Depending on what species/variety of holly, it may be toast. There are hollies for which 0F is not a problem but yours was likely not one of them.

If you want a more solid holly for the future, try these ones...
The shrubby Blue Hollies (Ilex x meserveae)
The shrubby Inkberry (Ilex glabra)
Long Stalk Holly (Ilex pedunculosa)
Any of Dr. Orten's Rutgers American Holly selections

In my yard, only Blue Holly and Long Stalk Holly came through with very minimal or no leaf burn. American Holly had severe leaf burn but the twigs look ok. I don't grow Inkberry. This winter was very bad for us (duration) but even in a normal winter we'll hit -15F at least once.

A lot of the Nellie R. Stevens hollies here have about 20% leaf dieback, mostly at the tips. This has just shown up the last few weeks.

The straight Ilex cornuta I have looks fine, though.

Here's my holly list in order of damage:
I. vomitoria 'Hoskin's Shadow' 20% light bronzing/purpling (in a very exposed spot, full sun on small berm)
I. aquifolium 'Ingramii' 20% light bronzing/purpling
Ilex 'Sand Pond' 10% very light bronzing
undamaged:
I. 'Venus'
I. 'Scepter'
I. 'James G. Esson'
I. 'Longwood Gold'
I. X koeheana 'Ruby'
Ilex 'Hohman'
Ilex 'Ajax'
all I. opaca, cultivars and natives

This post was edited by davidrt28 on Thu, Apr 10, 14 at 22:20

I'm having the same issue as well. About half of the tree the leaves are all brown and crisp, falling off. The back half, against the house, still has some green. There are shoots growing up out of the top of the ball shape where the main 'trunk' of the shoots have turned black. I am located in Ohio and we also had a very harsh winter. Is this a safe time of year to trim back the shoots growing out of the top? Should I cut off all the black? I'll take a picture later today to post. I didn't see any buds on it last time I looked, but I will check again.

I'm in Zone 5 (central PA) and I had holly trees around 6 ft tall put in last year. They looked fine all summer, fall and even part of the winter. In late Feb. the leaves turned brown/black and now the leaves are 95% gone. My poor trees are naked! I do not see any new growth or potential for them to come back.
I'm pretty sure they are DEAD - luckily, the landscape company will replace them, but if it's the type of holly they put in - I think they need to use a different variety for my location and the strong winds that I get.

We also had a horribly cold winter and where my house sits it's like a wind tunnel.