In a large bowl whisk together cream cheese, Greek yogurt, buffalo sauce and ranch powder.
Add cooked cauliflower, shredded chicken and cheddar cheese to the cream cheese and Greek yogurt mixture. Mix to combine.
Spread chicken and cheese mixture evenly in a large 8x8 or 9x9 baking dish. Top with frozen tater tots, covering the filling entirely. Bake for 30 minutes until tater tots are golden brown.
Remove from the oven and sprinkle evenly with shredded Mexican blend cheese. Return casserole to the oven and bake for 3-5 minutes until the cheese is melted.
Serve with a drizzle of ranch dressing or a dollop of Greek yogurt or sour cream!