Heat the olive oil in a skillet over medium-low heat. Add the sliced onion and cook, stirring occasionally, until soft and deep golden, about 20 to 25 minutes. Set aside to cool.

Preheat a smoker to 250°F. In a large bowl, combine the venison, ground pork, egg, breadcrumbs, milk, Worcestershire sauce, salt, pepper, and garlic powder. Mix gently just until combined.

Lay a large sheet of parchment on the counter. Shape half of the meat mixture into a rectangle about 9 by 6 inches. Arrange the cheddar sticks down the center, then spoon the cooled onions over the cheese, leaving the edges clear.

Shape the remaining meat mixture over the filling. Pinch the edges and ends together to seal the cheddar and onions inside. Form the loaf into an even shape so it cooks consistently.

Lay the bacon slices side by side on a clean sheet of parchment, slightly overlapping them. Place the meatloaf seam-side down across the bacon. Wrap the bacon around the loaf, tucking the ends underneath.

Transfer the wrapped meatloaf to the smoker. Smoke until the center reaches 150°F, then brush the top and sides with half of the barbecue sauce. Continue smoking until the center reaches 160°F, checking with an instant-read thermometer.

Brush the remaining barbecue sauce over the bacon during the final few minutes of cooking. Let the meatloaf rest for 10 minutes before slicing so the filling settles and the cheese is less likely to spill out.