When ready to cook, start the Traeger grill on Smoke with the lid open until the fire is established (4 to 5 minutes). Set the temperature to 225 degrees F and preheat, lid closed, for 10 minutes.
Mix together carrots, celery, mushrooms, and onions in a bowl and drizzle with olive oil. Cover bowl with plastic wrap and microwave for about 2 minutes to soften vegetables.
Let vegetables cool and then mix them in a large bowl with the ground beef, garlic, thyme, egg, crumbled cooked bacon, Worcestershire sauce, salt, pepper, bread crumbs and tomato soup.
Form the mixture into a loaf and place on a wire rack over a foil-lined baking sheet.
Make your bacon weave using the bacon, weaving it on a large piece of parchment paper.
Gently flip and lay the weave on top of the meatloaf so that the parchment is on top. Peel off the parchment paper.
Cook the meatloaf on the grill for 45 minutes. Remove the meatloaf from grill and increase temperature to 325 degrees F. Allow Traeger to preheat, lid closed, for 10 minutes.
Once grill comes to temperature, place the meatloaf back on the grill and cook until the internal temperature reaches 160 degrees F on an instant-read thermometer (about an hour).
During the last 15 minutes (once meatloaf reaches about 140 degrees F), brush the meatloaf with barbecue sauce to caramelize.
Remove from grill and let sit for 15 minutes before slicing. Enjoy!