You can select sub assembly from Design Explore when Manual Explode is active - the whole sub assembly (all components) can then be dragged together.
David, That's really nice. There seems to be a trick to it though. First one of the components of the sub assembly should be selected in the assembly workspace to get the Triad, then select the sub assembly in the Design Explorer. And finally select and move the Triad to move the entire sub assembly.
I found that I can even move parts that are patterns or groups, like fasteners - nuts, washers, etc. using the same technique. Select a first part to get the Triad, then Shift-select the list of items in the Design Explorer and finally select the Triad and move all the parts.
I hardly ever use explode so when I did use it I wasn't using it in the most efficient manner. Thanks for the tip.