Watchdog with long on and off periods for microcontroller
A 32 bit timer at 32768 Hz will give you that kind of time period (up to 36 hours.)

Maybe a Silego GPAK3 could do it. It has logic, counters and an internal clock reference that together could make that long of a resettable timeout. In volume they’re about 15 - 20 cents. And they’re really small.