I spent some time last night looking at the Sylvi projects on Ravelry. There are some beeeeeautiful coats that are completed. I decided to stick to the pattern, hood and all. The only modification I think I will make is I am not going to put buttons and button holes but am going to use clasps. There was a hunter green with pewter clasps that just looked lovely.
For anyone "upsizing" the clasps rather than button holes will give you a bit more ease because there is no overlap.