Preheat oven to 375 degrees.
Lightly coat each potato with vegetable oil, sprinkle with salt, and pierce a few times with a fork.
Place potatoes in oven and let bake for 1 hour, or until potatoes are cooked completely through and they have crispy skin.
While potatoes are baking cook bacon in a skillet, drain fat, and crumble.
Remove potatoes from oven and let rest till cool enough to handle. Slice potatoes in half lengthwise and scoop out the interior, leaving just enough to prevent the potato shells from collapsing.
In large bowl combine potato flesh, ½ cup of cheese, 2 tablespoons of chives, along with butter, salt, and pepper. Add crumbled bacon, reserving some crumbs for topping.
Mash potato mixture until smooth and slowly incorporate milk while mashing until you reach the desired texture. (Since potato size varies it is OK if you don't use the full ½ cup, or if you add a bit more)
Spoon potato mixture back into the potato skins then top with remaining cheese, chives, and crumbled bacon.
Place on a baking sheet and bake potatoes on the top rack for an additional 15 minutes.
Remove from oven, let cool slightly and serve.