Heat the grill to medium.
Spray two disposable pie plates with cooking spray and spread the tater tots evenly in each. Grill for about 20 minutes, stirring regularly. Set aside.
Meanwhile, fry the bacon in a sauté pan over medium heat, then place it on a paper towel-lined plate to drain excess grease.
Make the cheese sauce: In a deep-walled sauté pan over medium heat, melt the butter. Sprinkle in the flour, whisking to combine and create a slurry. Gradually pour in the milk, whisking continuously, to form a thin sauce. Gradually stir in the cheddar and chili powder until everything is well combined. Remove the sauce from the heat.
Layer the tater tots into small bowls or wide-mouthed mason jars. Top with cheese sauce, bacon, sour cream, and chives. Repeat the layers until you’ve reached the top of the containers. Enjoy your adorable tailgate tots!