A really warm coat that won't make me look huge?

[Dunwhingin]

Help please
I have to go to Berlin for a week where it is currently -12... I don't have a warm coat, I tend to run to the car wearing 4 jumpers..
But it is a work trip, I need to wear a suit so need a warm coat for over the top..
I like this
www.johnlewis.com/fat-face-lauren-lightweight-puffer-jacket-phantom/p1133495
But it's a bit short
This is perfect but a little pricey..
www.zalando.co.uk/roehnisch-chara-long-winter-coat-blue-r6341b01d-503.html?wmc=AFF_AW_EN.79682_..&awc=3356_1329759347_2f178317dc18edf08a1183eb21a0ccc4&wmc=AFF44_AW_EN.79682_..&awc=3356_1390776473_71d026265400af1fd986f4cd0b5a344a
Have any of you spotted/bought anything good recently?
That you

I have a Barbour Arctic Parka. My sister wore it to visit the Northern Lights last year and has it undone in many photos. It's super warm and as smart as one of those jackets will ever be.

Thank you, I'm bidding for a couple on eBay after your suggestion.