I don't think there is a life expectancy of Malignant Hypothermia. If there is.. it's based off the early deaths due to the people not wearing medical alerts or not knowing they had MH. Because I genetics for MH came from my grandmother's side and she is 99 years old this April. According to my theory basis you can live a very long time if you know you have MH and take all the precautions needed in-case emergency should arise.
I broke my nose and had an operation to correct it and awoke in intensive care in a different hospital. I was lucky the anethastist new what it was. Then I had a musel biopsy couple of months later to confirm.
Then my mum, grandma, my two ...