That's really hot. A Novak will shut down around 180 degrees, but I don't think the LRP ESC (or motor?) has the shutdown circuitry. With it getting that hot, I wouldn't expect the bonded magnets in the rotor to last very long. If it's allowed, you might consider the sintered rotor. Just keep in mind you'll have to gear it higher than the bonded.
Edit: Ooops, I see you're already considering the sintered. It will give the motor a little more torque than it has currently, but in general, you shouldn't have to worry about heat with that rotor.