Personally, to me sporadic usage is a couple times a month, as opposed to several times a week.
I'm using the online version. I'm on Windows 10. To find the note width settings, if you look in the top right corner you'll see a button with 3 dots ( . . . ). Click on it. You should see an option for Note Width. If you hover over that, you'll get 2 options: Optimize readability or Fit to Window.