Change Root Transform Rotation at Runtime to adjust for a 180 degree turn

I've been trying to figure out a way to rotate the running animation of a Humanoid avatar after a 180 degree turn; pointing the character in the opposite direction (https://www.mixamo.com/#/?page=1&query=180+turn).

Blend this back into the run doesn't work as the run animation is facing the opposite direction. The Root Transform Rotation can be changed (+180 degrees) however, if this can't be altered at runtime it would mean creating a new set of all the animations I have with the Root Transform Rotation alterations.

Basically, I'm wondering if there is a way to access the Root Transform Rotation value at runtime via AnimationClip, etc or if there is another solution?

Thanks