Only speculation fratemate that is all. But with all due respect, a failed system exposed to 7 hours of -40 versus 1 hour of -40 temps would be a difference. I am not rated on boeing so I ask: does the failure of a HYD C sys result in a "Land ASAP" situation or Emergency status.
And yes I do agree in this situation to continue the flight with the given public data so far available.