I have purchased this gore xenon 2.0 SO jacket
Its a great cold weather garment. I think the first time I tried mine it was a crisp morning, starting about 5°. I had an aldi base layer on too. After about 30 mins it was up to about 7 or 8° and I was sweating buckets! I had to take the base layer off, wring it out and stuff it in a back pocket. I found it hard to calibrate how thin and light it was to the protection it gave. I should also mention I was wearing matching gore xenon bibs - also well recommended if you plan on a lot of cold miles.
When you first put it on the sleeves will seem waaay to long, but once in the riding position they will just seem too long. But when the gloves are on you can use the length to get a really draft proof seal.
I am chubby so provide myself with some under skin insulation - skinnys might find they need a base layer earlier.