Cook the bacon until crisp in a skillet or oven. Drain on paper towels and crumble.
Boil the potato chunks in well-salted water until just tender, 10–12 minutes.
Drain the potatoes, spread on a sheet pan, and let steam-dry and cool slightly.
Whisk sour cream, mayonnaise, vinegar, Dijon, garlic powder, onion powder, paprika, salt, and pepper in a large bowl.
Fold warm potatoes into the dressing until coated without mashing.
Stir in cheddar, green onions, and half the bacon. Adjust salt and pepper to taste.
Chill 30 minutes if you can. Top with remaining bacon and chives before serving.