All

I run commute to and from work most days - this morning (26th Feb) as you can imagine, it was pretty darn cold on the run along the Thames into the city of London, but I was layered up with baselayer, midlayer and running jacket so was relatively toasty (once I got started)

However, I only run with a very small specialist running backpack as I really don't like backpacks in general when running but it has my shirt and assorted sundry items to change into, post shower, at the office. As I got into the office this morning I realised my lightweight running jacket wasn't going to cut it at lunchtime given it was about -3c (and I was right) so ideally I'm looking at warm jacket I can stash in my backpack which doesn't take up any space and add weight - I was looking at the NorthFace Thermoball which is a very lightweight warm jacket which apparently can fold up into its own pocket. Looks perfect but at around £150 has anyone any experience with them, or any others?

I have a wardrobe of outdoor jackets, but this is a specific need!

Oh - and yes, I have often brought in and left jackets in the office, but then inevitably they get taken home and don't always come back in a timely manner. Current Fleet:-
2018 Discovery 5 3.0 HSE
2021 Ford Ranger Wildtrack
2019 Ford Mustang Bullitt 5.0 V8
1993 Defender 90 200TDI Pickup

Gone - not forgotten
2016 L405 4.4 SDV8 Vogue SE
2012 L322 4.4 Westminster
2004 L322 4.4 V8 Autobiography LE
2000 P38 RR 4.0 HSE (ex Clarkson test car)