Do what you need.
I don't take a chair. It's another thing to pack and it's heavy. Retreat center chairs are not comfortable and don't turn around for easy getting in and out OR talking to the person behind me. I use a Gypsy Sit Upon. It takes getting used to. I like that it isn't stable so my core muscles are gentle working and I don't get back pain. It adds ~2" to height. Even though I'm tall, It helps me be at the right height for my machine that's sitting on top of a table (not down in my table like at home). Also, because my lower legs are long, on a retreat center chair, I feel like I'm sitting in a hole and that ruins my posture, making back pain worse.
So....Do what you need.