I was very glad that J. chose Hedwig for Halloween this year because this was a fun costume to make (and it didn't involve satin, woo hoo!).
J. is happy with it (whew!) and I think it will work well for Halloween -- it's pretty warm on it's own but she should be able to wear it at school with just a t-shirt and leggings. Then she can put on another couple of extra layers for trick-or-treating. She did request a full length white dress to wear underneath but I don't see that happening, lol.