Rust, how far to cut.

[ngnaz]

I am sure this has been addressed somewhere but a search did not answer it and every case is probably different so I ask for any expertise you can help with.

The drivers side rocker was definitely rotted to a point where I replaced it. The passenger side was about ready to go under the knife until I started cutting and realized that the rocker itself doesn't have any rot and not even bubbling but the rear lower front behind the rocker is rotted away.

I assume that there will be residual rot that is unseen as there always is but in your expert opinion, should I cut out the entire rocker or try to repair just the quarter and the support behind it? I have all of the repair pieces but would rather not cut any more than is needed.

What do you think?