Mr T should also have asked how old the battery is. 5 to 6 years is the onset of it's end of life and cold WX does add to the poor old thing's stress.

 

Does it crank and crank without starting? or is it hesitant to crank? with a battery that was new this summer, your battery is most likely not the cause (unless you were unlucky and got a bad one). Mine sometimes takes a few cranks to get going on cold mornings. I've found that if I give the fuel pump time to prime, it starts a little faster. So you might try letting it sit for like 5-10 seconds with the key turned on, but not cranking and see if that helps it start faster.

You also might have a look at your spark plugs, spark plug wires, and coil, especially terminal 3 if you have the oem coil as it's prone to corroding.

 

I had this exact same issue (albeit in another german car) last winter. New battery didn't solve the issue. It turned out my starter was dying. All the symptoms were weak cranking which made me think battery. If the car is cranking, I wouldn't suspect wiring. Either battery or starter. If the battery is good, go after the starter.