Overwintering Azalea Bonsai

I have to ask you all...what are your overwinter practices for
your azalea bonsais? I know that it would be ideal
to put them in an unheated greenhouse. But what if you don't
have one? Some people say you can put them in the shed or
unheated garage. But wouldn't those environments be too dry
and wouldn't the air be too saturated with mold spores? Please
advise. I can try spraying them with antifungal sprays. But I
left one outside in the winter and it is okay. On the other hand,
I don't feel like gambling on the weather since it can get below
20 degrees F in New York during winter. I live in zone 7.

Beezoism

I have successfully wintered Satsuki azaleas in an old well house. This is a bump out from the foundation of my home, unheated, below ground, normally dark and damp. It hovers between 25 F and 40 F all winter, usually 32 to 38 F, but in very cold weather it will drop to as low as 25 F. I added a small, inexpensive fan, it gets turned on in Nov. when the trees get put in there, and is turned off when the trees are taken out. The fan prevents issues with mold and fungus. I point it at a wall, so the breeze is deflected before hitting the trees, but the air in all parts of the room is moving, grassy leaves will waive a bit in the light breeze.

I did not bother adding lights the first few years. Later I added 2 shop lights, 48 inch T 12 cool white fluorescent tubes, total 4 tubes. The are cool enough they don't heat the room up. The small amount of light makes me feel better for the evergreen Satsuki and the more tender, shohin size Cork Bark Japanese Black pines. I doubt there is a whole lot of photosynthesis going on, so the lights are probably not necessary, but it makes me feel better, and that is important.  

One year I experimented with a high intensity light, a 400 watt HPS lamp that does produce enough light the pines would interpret it as about 50% shade, some 2000 ft candles at the height I had it above the foliage. This proved to be a bad idea. It generated too much heat, had problems with dehydration and with the room staying too warm. The survivors of this experiment took a couple years to recover.

I do think if the trees are cold enough to be fully dormant, no light is needed.

It is critical to keep air movement, to avoid issues with the soil stagnating, and issues with mold, mildew, bacterial rots, and various fungal infections. It does not have to be a strong breeze, but air movement should be strong enough to feel with your hand. The trees will tolerate a fairly strong breeze, if you keep an eye on watering.

Once I added the fan, never had a problem with fungi again.