I am more pessimistic and think Catherine will survive, but will have been betrayed by Clare, which would be the worst.
And because of this and Ryan wanting contact with his father Catherine will retire with no one she cares about being part of her life any more.
Maybe the landrover or whatever it was, will be her lifeboat and it will finish with her driving off into the sunset on her own, bitter and no longer able to make sarcastic jokes.
A life dedicated to others, and no thanks in return.
Alternatively she pairs up with Nevison and they sail off on a grand global cruise