The Panthers owe Rhule about $40 million. So, if he does not find a head coaching job, he would make $844,000 per month. $10 million/year for doing nothing.
Honestly, why would you bother with the hassle and stress of going back into coaching? He, quite literally, never needs to work another day in his life. If I just had the itch to compete, I'd volunteer coach at a high school.
Whatever he makes at his next coaching job will negate that portion of the buyout from the Panthers, but nobody's gonna pay him anywhere near $10 million/year, so the Panthers are still gonna be on the hook for a significant portion of his salary.