I bought an adapter 4 weeks ago and I think it's a perfect fit for you. It runs a standalone Android system which allows you to run two applications at the same time. It supports split screen, so that you are able to use your favorite App while navigating with Google Map. After you use this, you don't need to use CarPlay.
Now as you were asked above. Is the blogging app available for android system?
If the blogging app is available for android system, It might be a little cheaper than phone change.
Link is here, FYI
https://carplaysmartbox.com/products/app-download-ai-box-wireless-carplay-adapter-screen-mirroring-factory-chevrolet-explorer-cruz-malibu