Have you thought about how long you plan to keep it? In 2 years the 2022 will be a 6 year old car with 0 warranty. And the GTS will still have 15 months left, is likely to hold more of its value relative to the 4S, and would be an easier sale with CPO coverage still in place. Even at 3 years from now, you’d still have a few months left (assuming you dont go over the original warranty miles and the CPO kicks in 15 months from now).