I just googled that question and found this. Basically you get two off-center rainbows. But since it is normal for us to also see double rainbows, you could end up with quadruple rainbows.
But since that is too busy, you could just do two off-center rainbows. And you probably could make them skinnier than I’m making them.
It would still end on a binary sunset, but maybe you could see a subtle rainbow in this one shot.