Hi longshot,
I don't touch them until august - if they are alive they'll come back .
In 2011, I started cutting the branches on a tree, and all of a sudden I knew I shouldn't have cut the last branch ... But it was too late.
The branch looked dried, but it was not as dry as the other ones. That is how I knew - so basically, you know when you cut them and not before.
So for me, the best approach is to not cut until august .
As for die back on branches, I'm really deceived .This winter was mild here - min night temp of -10°C/-15°C - , and I see dead buds on my BT but not on "goutte d'or" ... Go figure ... Isn't BT supposed to be the cold hardiest strain ?
My BT and my goutte d'or are 5-10 meters away one from the other on the same line...