As a groomer, I get asked a lot "Do you think she'll be cold since it's winter?" Generally, dogs in the winter only go out to potty, or when their owners go out. A dog will still go potty where it's always pottied, and being on a walk with you or something, you'll be able to tell.
However, people generally keep the inside of their house warmer than the AC keeps it cool in the summer, if that makes sense. So your dog is pretty much going to spend most of her time in the warmer house.
I actually suggest medium coats for the winter, since the dog will still stay warm (dogs can take cooler temps than you think, just dont LEAVE them out there) and they won't have snow sticking to them.
My parents mutt, Precious, is a boxer pitt mix. Both breeds have very short, coarse hair. When she's wet, she's PINK and polka dotted all over. She looooves the snow.. though maybe it's all her fat on her. Who knows. (:
Aw, I miss taking pics of her, she was easy, didn't mold into the background like the poos, lol.
Just keep her at a length YOU like. She'll be fine.