Answer: The rule of thumb is never to remove more than one-third of the live growth on a shrub during any pruning session. If the lower stems are bare they may never produce new stems and leaves so be careful how much you prune - just take off one third of the topmost growth. I have had the experience where I've completely cut overgrown azaleas down to the ground and they have resprouted - but this may not work for you, especially if you plan on digging them up and replanting them. If there is a reason for saving them rather than replacing them, then prune and dig with caution, and plan on nursing them back to health after the move.
Best wishes with your azaleas.
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