Gorgeous! The only 70cm that I have is actually an LV scarf (I missed the non-H week) but it's a great size. I need to start hunting some of the vintage ones.
You should! (PS- there's one for a decent deal right now on fashionphile) one thing I like about them is they are very flexible. They can have a slightly larger look if you tie them more like a 90, but you can also pleat them down and do a zBova knot and then they only take up as much neck space as a bandana. (And thank you!)