Place the cubed potatoes in a large pot and cover with cold water by about 1 inch.
Bring to a boil over high heat, then reduce to medium and simmer until potatoes are tender when pierced with a fork, about 12-15 minutes.
Drain the potatoes and let them cool to room temperature.
While the potatoes cook, cook the turkey bacon in a large skillet over medium heat until crispy, about 6-8 minutes, turning occasionally.
Transfer the cooked bacon to a paper towel-lined plate to drain, then crumble into small pieces once cooled.
In a large mixing bowl, whisk together sour cream, mayonnaise, Dijon mustard, apple cider vinegar, sugar, garlic powder, onion powder, salt, and black pepper until smooth and well combined.
Add the cooled potatoes, crumbled bacon, shredded cheddar cheese, and sliced green onions to the dressing.
Gently fold everything together until the potatoes are evenly coated with the creamy dressing and the ingredients are well distributed.
Taste and adjust seasoning with additional salt and pepper if desired.
Cover and refrigerate the potato salad for at least 1 hour before serving to allow flavors to meld.
Serve chilled or at room temperature.