1. Preheat the oven to 400°F. Arrange both racks in the center, equidistant from the top and bottom.
2. Scrub the potatoes, poke a few holes in each one with a knife, and wrap only the sweet potato in foil (leave the russets unwrapped). Bake on the top rack for about 1 hour, or until soft in the middle when a knife is inserted.
3. While the potatoes cook, cover a rimmed sheet pan with foil (for easier clean up). Place a wire baking rack on top of the sheet pan. (The rack is optional, but allows for the bacon grease to drip below.) Squeeze the bacon slices side by side across the rack or pan. They may slightly overlap, but that’s ok. Bake on the bottom rack for 20-25 minutes, or until bacon is cooked to desired doneness. Let cool, and then chop or crumble into small pieces.
4. When the potatoes are done, let them cool enough to handle. Cut all of the potatoes in half completely. Carefully scoop out the flesh with a spoon and place in a large mixing bowl, making sure to leave a bit of the flesh around all sides to keep the potatoes intact. Discard the sweet potato skin but keep the others. Place potato skins in a greased 9×13 baking dish.
5. To the mixing bowl, add the chicken broth, butter, Greek yogurt, salt, pepper, and chives. Use a potato masher or the back of a fork to mash and combine the mixture. Using a spoon, stir in the cheese and the chopped bacon. Scoop the mixture back in to the potato skins evenly. The stuffing will heap over the tops (yum!). (Freezing instructions begin here.)
6. Increase the oven temperature to 425°F. Bake the potatoes, uncovered, for about 20 minutes, or until heated through and golden brown on top. Garnish with more minced chives. 

Freeze For Later: Complete Steps 1-5. Cover the 9×13 baking dish with an air-tight lid or with a few layers of foil or plastic wrap to seal tightly. Freeze.

Prepare From Frozen: Thaw potatoes in the refrigerator for 24-48 hours. Bake according to Step 6.