Just found this little Jem https://www.canon.co.uk/support/consumer_products/operating_system_information/ Great tucked away somewhere, hey guys we posted that you should check before you upgrade - only it refers to Sierra not High Sierra.
Have been a happy Canon user for years, all my camea gear and printing is done with Canon. Yesterday I had a perfectly working MG6150 with new ink. Today I finally did the High Sierra upgrade, clean install so had to redownload drivers and brilliant ...