Originally Posted by
WilcoRoger
As someone jumping regularly between -20 and +30 (check my location

), I'd say why do you need the coat in London? Your meetings would be indoor activities. You'd go to those meetings and the airport in a heated cab. You'll drive home in a car. Where will you need the coat?
As I'm sure I said, to start I have a 10 min walk to the station then a 75min train ride that may or may not have the heating on. I then have meetings dotted around the place that will involve walking outside between venues as they're too close to get a cab between.
I've also had suits ruined by rain before, so am mindful of this - forecast for this is currently sleet and 0C. Anyway, I now reckon it'll go in my carry-on so the problem is solved.