@hash4u
In my own home, i have Corolla with odometer 410,000+ with original sealed engine(Factory fitted gasket).
Of course other maintenance works done but Alhamdolillah engine has not opened yet for rings, pistons or gasket work ever.
Of course, there is oil reduction nowcwhich actually started after 300K but that is also minor and bearable.
I am thinking it to stretch to some more kilometers on sealed Engine.
Timely maintenance and proper care is the key to long life