It's too hard to move whole branches on large trees

I have a large tree, and I can't move a branch to a different parent because it's way off the screen.  If I zoom out the grab points disappear, or I can't read the text of where I might be wanting to drag it to.

The usual solution is that that when I drag something and hit the edges of the screen it should start panning in that direction.  Currently dragging just stops.