DropBarFan

Yeah, in another thread I read about the nice mid-layer garments & now I see they're a general consumer trend too. Makes sense, they're comfier & more convenient than trad pull-over knit sweater. & if it's really freezing one can use a heavyweight underwear top, they zip up the neck which helps stay warm.

JaccoW

The main reason why you see so many different answers is because local climatic conditions make a huge difference.

Any advice depends on absolute temperature, humidity and wind that you will be experiencing during your trip. Those last two being the most important.
10ºC/50ºF feels quite different depending on those two factors.

At -5ºC/23ºF I prefer a base layer, down jacket and a wind/waterproof shell when riding. But then again where I live the wind will probably be around 40kph/25mph, making it effectively feel like -14ºC/7ºF while the humidity is still around 80%. It's perfect even for longer rides though I do get a bit sweaty after a while. That last bit is mainly because the relative humidity makes it harder to get rid of moisture on a longer ride.

When I drove in the same temperatures in Berlin, where the humidity is much lower, I got less sweaty but it also didn't feel that cold anymore because there was much less wind.
I still needed thick gloves but I could ditch the down jacket and just ride around in a windproof jacket with a fleece on top of my baselayer.

I've had Russian friends that came from -30ºC temperatures almost freeze to death because freezing temperatures (0ºC/32ºF) near the windy sea are a whole different experience.

So unless you are riding in snowy/freezing conditions pick a thin puff jacket that you can easily layer underneath your regular jacket and perhaps ask local riders/outdoorsmen.
A store is usually a good place to start provided they are active themselves and know what they are talking about.

MichaelW

insulated synth jackets and sleeveless gillets are really good for cold weather extra insulation when you have to stop. A thin , stuffable layer takes up little room.

veganbikes

Nice! It was pretty much almost required wear at the outdoor shop I worked at. I don't think there was anyone who didn't work there for at least a year who didn't have one.

DropBarFan

Only been to Berlin once (was in winter, got to see the kewl Sechstagerennen) but I thought it could be pretty damp in Germany, fog is common in winter. But I guess by the sea is still generally more humid. BTW interesting that despite cold temps most of the local commuters didn't put on tons of outerwear.

My local Blue Ridge mountains can get very humid & foggy in the fall & that can be quite chilling even in moderate temps--even w/waterproof outer clothes the moisture saturates everything.

Biketouringhobo

Canari Everest softshell jacket
Craft Active baselayer

JaccoW

True. My semester in Berlin was the first time I experienced fog that lingered for a whole week. Where I live the wind causes it to disperse in less than a day.
Even during a storm it was rarely very windy. Being 5km or 200km away from the nearest sea makes a very big difference in that regard.

The main reason you don't see that much outerwear is because it rarely looks like outerwear.
Jack Wolfskin is to Germany like The North Face is to the USA, affordable outdoor gear.
The main difference is that most jackets look fairly casual while still having a waterproof membrane.