Managing color correction after the cut

So, I have my source footage. Each starts with a slate that has a white balance and several color match cards on it. I've finished my cut and want to start color grading. But of course, the slate isn't in the cut anymore.
The same problem applies to audio in some cases. I've already cut out parts (5 seconds of ambient noise to train the noise reduction SFX) I need during audio design.

How do I go about editing here?