You may get lucky and find someone in here that has taken the Barre course. But you may want to check with the actual course provider(s). I have not personally looked into the programs available. But when I want information on courses, I always check with the course provider. You might want to ask for information here with the specific name of the course. The more specific you are in this forum, the better the answers will be to your questions.
I cannot talk to the specifics about the course your are looking for but I may be able to answer the question on space since I also have a Barre certification.
It may be a little crowded but you could get away with just one 6 foot barre and have 3 people on either side of it.
Hope this helps.