Over the past month, my small trumpet jade plant has begun to experience a heavy bout of leaf drop. I'm wondering if this is normal or not.

I know that most jade leaf drop is caused by overwatering. However, since I bought the plant I have followed the same watering schedule. I wait three weeks between waterings, then immerse the pot in water until the soil is saturated. This was recommended to me by the provider as it simulates the sudden saturation of soil from heavy rains, and then the dry period following. The plant has always been happy and healthy with this.

Due to my great worry about losing my favourite plant, I did some reading and discovered that jades kept indoors may experience leaf drop in preparation for the growing season, late fall and early winter.

In spite of the leaf drop I have not changed my watering schedule. Has anyone else experienced a shedding jade indoors that simply does it because of the time of year?

I would appreciate any insight people could give on this matter. I intend to propagate the plant by rooting some leaves when I return home from vacation. I recently moved the plant back into the window as well; dorm windows here don't close completely, and though I stuffed the crack with fabric I'm worried about the plant getting overly cold. However, I also want it to get adequate light.