Updated last evening to Ubuntu MATE 18.10. Everything went smooth and my PC continues to work and work and work… as usual 
Performed the usual “after version update tasks”, e.g. updating & re-enabling Software Repositories, re-enabling the “ubuntu mate” grub theme via Grub Customizer, etc.
Ubuntu MATE simply rocks! 
Congratulations to the Ubuntu MATE team and THANK YOU SO MUCH for all your efforts! 