My guess would be it's moisture more than temperature. Ginger is tropical, so it wouldn't probably be used to big temperature swings. But, many tropical areas have a wet and dry season - that might be what triggers dormancy.

I have potted gingers. In the fall, I quit watering and then cut the tops off, and store the whole pot in the basement over the winter. They do try to sprout a little bit in storage, but without light and water, the sprouts just get a few inches tall before it's time to take them out in the spring.

Thank you. The ginger is now in the house next to a south-facing patio door.

One of them is even putting up a bloom-spike!

What kind of fertilizer do you use for your ginger?