Happily, I've found a new set of classes to fill the gaping void that was left behind:
Beginning Ballet classes taught by Kathy Mata @SF Dance Center.
The classes are great and despite being called 'Beginning', there are more advanced dancers that also attend the class (a very good sign !). Kathy is a teacher very mindful of everyone in her class at all times, offering helpful corrections and advice for the duration of each class. I can feel that I'm making technical progress since starting the class (a very good feeling). A happy start to a new chapter !