We had 2 nights where temperatures dropped to 23 and 21 degrees last week. All of my in ground trees which either had emerging leaves or green swelling buds look dead. The leaves are black, the small figlets are brown or black and although we have had several warm days since then, I see no evidence of bud growth from nodes what were still more dormant than awake.

I have figured out there will be no breba crop but am concerned that I am not seeing bud growth. What is the chance that the above ground growth will rebound or am I likely to find that I should cut everything down and just wait for new growth to come up from the roots? Trees vary in age from 2 years to about 10 years although the older trees were trimmed to ground level last year when I was visited by the Ambrosia Beetle. Despite that, they grew to around 6' in height and produced a nice crop although it was a bit later than usual.

New buds should emerge.  I wouldn't cut anything until early summer to clearly see what has died.

Marianna, your trees will be fine. My in-ground trees have not started to swell. But my garaged container trees have leaves and lots of growth. Saturday morning, I spent then entire day hauling my container trees back inside. Some one gallon trees I left outside were fine thanks to my help! I placed them under a set of wooden tables and completely covered the tables with 2 large and long frost blankets. It worked! Not a leaf lost thanks to those blankets. Next year, I'm gonna wait till Easter week to start moving trees out.

Dennis and Frank, Thanks for the reassurances. Seems sort of weird that zone 7b would be budding out before 8a... but then most of the varieties I am growing are pretty cold hardy and perhaps they do not need as much heat to come out of dormancy. They are planted on a SE facing slope.

Thought I had pretty much escaped winter damage this year.  Although a few of the terminal buds were damaged, a node down and the buds were swelling and I was even seeing the emergence of some leaves on some of the terminal buds. Have definitely been in a purple funk seeing all the new growth turn black.

Hi MariannaMiller,
Did you already have stem-growth or only one or two leaves ?
I had a leaf on one in the basement beginning March, and decided to punish that - ok, because I had no more free space upstairs -, so I put her in the garden.
The leaf turned black and dried. The terminal bud died as well . But now several buds are already greening on that small potted tree all along the older part of the stem.
I had to slow her, and that was IMO my best move .
Time will tell .
So, no trimming on your trees for now, IMO only the last node got damaged, and all nodes below are waiting for their turn to wake up, and they surely will . Patience ...

jdsfrance: Had some small leaves from the terminal bud and low on the stems where it looked like new branches were going to emerge but no stem elongation that was noticeable.  For the most part where there were no leaves (older and larger plants), the stems had just gotten very knobby with bits of green showing on the buds and figlets smaller than a pea. I had just put some of the babies which had been buried for the winter in ground about 10 days ago because they were starting to wake up and I figured they would be better off finishing the process in the location where they were to live from now on. All of those had terminal buds which were already leafing out and buds showing various amounts of green at all the nodes.  Up until the freeze we had nights in the high 40's and 50's with day time temps in the 60's to high 70's.