I grow ginger outside here in New England, but I make a little hoophouse for it. I close it up when the temps are too cold. It does well this way.

John Kempf explained in a lecture that red color on a plant is a sign of stress. Trying to avoid stressors improves the plant's production ability. Stressors: too cold/hot, not enough light, too wet/dry, poor soil/not enough nutrients, transplanting on to larger pots before final planting, keeping plants in pots too long before planting, etc.