you should be... it can happen, even in the dead of winter.
again, the tire pressure noted on the tire is going to be the MAXIMUM - tires heat up when driving, yes, even in cold weather... heating increases pressure. thus, you do NOT want to run the tires at the maximum pressure indicated on the tire..
google search says ~25% under or over the recommended pressures of the vehicle... so yeah, about 40 is going to be the tripping point.
otherwise, short of taking it to a dealer to have the monitors reset not much one can do.