I can see I'm not the only one in Norway to help you Brits - GOOD!
Bullefnatt is up there, and he know how it is down here too!
If you freeze when you ride your bike; Gerbing Electric Clothes!
And 2-3 layers of wool - don't forget longjohns made of wool!
And long socks made of wool - we call it ''skistrømper'' = long socks made for go skiing, made of wool.
And neoprene, like the underwear from BMW; wear one pair of wool tights next to your skin, and the BMW neoprene underwear; good!
If you find out far from home you freeze at the upper part of you legs when you ride;
wrap one t-shirt around each leg, or a newspaper - it helps!
And put a newpaper inside you jacket as high as you can; if the centre bone in your chest gets cold, then you are cold too - and perhaps you get a cold.
Electric heated gloves feel much more comfy then heated handle bars - I know! And they are much better in rain too!
But to put a thick rubber glove, the type they use in industry (chemical, making concrate and so on, not the thin dentist type of gloves) helps too - make sure you put it on BEFORE it starts to rain!
And rain covers for boots helps too.
But:
Sometimes it's hot, even in Norway!
If you ride with you jacket open, you get a cold centre bone in your chest.
That feels OK at once, but after a few kilometres it gets too cold, and you may get a cold.
Put a newspaper or a plastic bag on your chest, and ride with you jacket unzipped 50% - that way you get some air inside you jacket, not a cold centre bone, and you are still protected by the jacket if you hit a deer or other natives.
And a neck warmer, balaclava, made of Windstopper - that is sooooooo good!
I wear one with a hood, and one hoodless at the same time; the inside of it feels cold to the skin in my neck, so wearing two is best, specially in rain and real cold days.
They are expensive, but I can't live without mine - buy two!!!!

Liv.