My moms has done three and each one all they did was a walk away after the large group meeting. Hers were about 3 hours and when they were done they just stood up and walked out. Two three nights and a 4 night. She doesn't even care and takes a book or knitting with her. If you have no problem saying 'no' a lot (hopefully not a lot) and can zone out for a few hours, I'd say go for it.
