I bought an azalea for 4$ from nursery stock. the leaves were pretty yellow, and I knew it was sick

. When i took it out of its pot the rootball was crazy thick, and it had obviously been in there way too long. I raked out the roots, took off a good chunk of the rootball, defoliated some of the really undesirable growth, re-potted it in a regular non-bonsai pot, and fertilized it. now the centers of the leaf clusters are sprouting tiny green healthy-looking leaves.
My question is: Being that it is winter in the pacific northwest, what is my course of action? Do I defoliate the yellow leaves to increase vigor, do i defoliate the new stuff to encourage back-budding (or is it too early for that)? How long do I wait for my tree to get healthy to get in to some more serious shaping?