Well, after our first trip in ages, I had forgotten how useful Sidecar is. This lets an iPad act as a second screen for your Mac. I had nearly forgotten how to use It, but it isn’t too complicated, if you turn on wifi it just works over that, and with macOS Big Sur, you just click on the settings at the upper right and then display and click and you will see sidecar settings, and then “Connect to <Your iPad” and you can sling it to the left or right with the display arrangement. Useful stuff!