That wouldn't be too much for me at all. I'd be wearing long sleeve wool under the jacket, too. The jacket has vents and/or doesn't flop too much with the zipper partly opened, yes?

I would also want some pretty significant gloves (but then, I have a touch of Raynaud's - I'd be wearing my Ibex Kilo II gloves) and a cap, hopefully a cap that's compact enough to get shoved into a pocket if it gets too warm.