Preheat oven to 400. Place the potatoes directly on the rack in the center of the oven and bake for 30 minutes. Pierce each potato in a couple spots and continue to bake until tender, about 30 minutes more. Remove potatoes from the oven and turn heat down to 375.
Cut bacon into 1 1/2 inch chunks and put in a saucepan. Cook over medium-low heat until crispy. Drain off fat, set aside.
Holding the potato with an oven-mitt or towel, trim off the top of the potatoes, forming a canoe-like shape. Carefully scoop out most of the potato into a large mixing bowl, leaving about 3/8 of an inch around all sides.
4. Mash the potatoes lightly with a fork, along with 2-3 tbsp butter and about 1/3-1/2 cup milk. Stir in bacon and green onions and season with salt and pepper to taste. Add 1 ½ cup of cheddar cheese, mixing well
Return the mixture to the potato skins, mounding slightly. Sprinkle the remaining cheese on top. Place potatoes on a baking sheet and bake until heated through, about 20 minutes.