Preheat the oven to 350°F (175°C).
In a large mixing bowl, combine ground beef, ground pork, breadcrumbs, milk, barbecue sauce, chopped onion, minced garlic, egg, Worcestershire sauce, salt, black pepper, smoked paprika, and chili powder. Mix until well combined.
Shape the mixture into a loaf and place it in a loaf pan. Top with extra barbecue sauce.
In a separate bowl, prepare the potato casserole by mixing sliced potatoes, sour cream, shredded cheddar cheese, milk, melted butter, garlic powder, salt, black pepper, and paprika.
Pour the potato mixture into a 9x13-inch baking dish, spreading evenly.
Place both the meatloaf and potato casserole in the oven. Bake the meatloaf for 60 minutes, and check the internal temperature; it should reach 160°F (71°C).
Continue baking the potato casserole for about 45 minutes, or until the potatoes are tender and the top is lightly browned.
Once done, let both dishes rest for 10 minutes before serving. Slice the meatloaf and serve it alongside the potato casserole.