I've decided to keep this as my own notes as I go along exploring Drupal 8 and hopefully this would help anyone.
Sadly Drupal 8 views does not have Theme options like in Drupal 7. Found this very useful article on how to tackle views theme in Drupal 8.
Drush enable/disable maintainance mode
Drupal 8 :
drush sset system.maintenance_mode TRUE
Drupal 7 :
drush vset maintenance_mode 1