I carry a clamp on cable barrel for broken cables but not sure how much good it would do for a broken throttle cable. Could swap the close cable for the open cable to get you home. I rode my bike home once holding the cable in my hand tied to an old bolt to make a T handle so I could pull on it to operate the throttle.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!