I had a coat with large side pockets just big enough to fit the 11" air. Not that I would ever use them for that, but it sure felt nice to have the option...

What OS? My air can't upgrade and is out of space with like nothing installed. Curious if still macos or something else, now.

You can upgrade the disk of a MacBook Air with a larger SSD and install newer MacOS versions with https://dortania.github.io/OpenCore-Legacy-Patcher/.

Thanks a lot for that link! I know nothing of Apple stuff and a friend has got an old iMac that he thought was unupdatable but it seems there's a way. Cheers!