Mix sausage and ground sirloin in a large bowl until thoroughly combined; add eggs, bread crumbs, onion, and ranch dressing; mix well. Form into a loaf and place into the center of a 9x13-inch baking dish.
Arrange fingerling potatoes and baby carrots around meatloaf and cover dish with foil.
Bake in the preheated oven for 1 hour; remove foil and brush meatloaf with barbeque sauce. Bake uncovered until an instant-read meat thermometer inserted into the center of the loaf reads at least 160 degrees F (70 degrees C), about 30 more minutes. Let meatloaf rest 5 to 10 minutes before slicing.