Help with rig's root transform!

So I have an rig here set to work as an IK, but I have one issue I would like to express and try to solve.

The pelvis bone is obviously the main parent and center of motion, but the rig root on the ground is invaluable for the re-positioning of the character. When animating a walk or a run the root transform is left behind, I can still use it, but since it was left behind it is pivoting the character from that point which is not ideal.

Long story short, how can I get the room transform to follow the pelvis but not effect the motion unless I move the root transform directly.