Reviving rootbound azalea

I put in some Karen azaleas this spring, and while I soaked the bushes before planting, one of them never did thrive and recently appeared to be dead. I pulled it up - easily, because it was totally rootbound - and was going to toss it, when I noticed that the wood was still green and alive.

So I've pruned it way back and soaked it and really loosened the rootball. However, it is now November in Zone 5b, and I don't know whether I should replant it in the garden, pot it and bring it inside to grow, or take the middle course and keep it in a cooler but protected place until spring.

Pretend it is going to sit as unsold inventory at a nursery during the winter. Water it adequately and place it outside until the night temps approach the low 30s to force it to go dormant. Then bring it into a protected place until spring. Do not let the pot be in direct contact with the cold/frozen ground. Water again twice a month or less, depending whether the location is heated or not.

Thanks, that's just what I need to know!

I guess I'm OK bringing it in now, as we've already had several days of frost.