I wasn't sure where to put this so chose the Solo Travel forum. I just changed my mind on a program, so released a Single Supplement for the Art History of Belgium and Holland tour date of Sept 20 2019.
This program seems to have a dearth of single supplements, in fact I signed up last summer for next fall just to get one. Meanwhile I did a Rick Steves tour in April and decided that I didn't need to go deeper into the Art History of the area so changed to a different program for this Fall.
There may, of course, be a waiting list but thought I'd put it out there for anyone who is interested.