Is it possible for me to plant a Yucca plant that I have had for many years, and is now extremely large outdoors? Will it survive in the winter months ahead if I do?
Since you didn't specify in which zone you are considering planting, the answer is, "It depends." The "indoor' yucca will tolerate rather cool temperatures, down into the 30's for stretches of time. However, if your winters have temps into the lower 20's or below more than 2-5 times a year, the yucca may not survive. You could plant and be prepared with blankets for protection in the coldest weather if it's infrequent. These are tough plants, and withstand more than you'd think. Just don't keep them really moist during cold weather.
Have you considered pruning the plant if it's too big? A sharp saw can be your best friend with these plants. At least that's been my experience. They send up new growth quickly and instead of single stems, they develop their own character when pruned.