Preheat a smoker to 250°F. Use a mild wood such as applewood so the smoke complements the fruit-forward glaze.
In a large bowl, combine the ground turkey, egg, breadcrumbs, onion, garlic powder, thyme, salt, and black pepper. Mix gently just until combined. Overmixing can make the meatloaf dense.
Shape the mixture into a compact loaf and place it on a sheet of foil or a smoker-safe tray. Leave room around the loaf so smoke can circulate.
In a small bowl, stir together the cranberry sauce, barbecue sauce, grated apple, and apple cider vinegar. Spoon about half of the glaze over the meatloaf and reserve the rest.
Smoke the meatloaf until its center reaches 165°F on an instant-read thermometer, about 1 1/2 to 2 hours depending on its shape and the smoker. Brush the reserved glaze over the top during the final 15 minutes.
Remove the meatloaf from the smoker and let it rest for 10 minutes before slicing. Resting helps the slices hold together.