I can't get puppies in the winter because of my lack of loving the cold. We've had these 0 degree temps and I'm SO GLAD my adult dogs don't need the same time/attention as a puppy!!!!!!
That said, you did get a puppy in the winter
so need to figure out a way to manage all that energy. I know I'd have tug toys all over the house so I can grab/play with those. PLUS I'd be taking one outside with me so AFTER the poops/pees if my puppy wanted to 'rumble' there was a good alternative to my clothing...
Are you able to find a puppy class in your area to attend? Be a great help at least once a week to help engage mentally and physically to tire your pup out. Plus actually making playdates with other friends with good dogs, or just friends that like puppies so you can visit.
Things to work out in the home are ---> Top Training Expectations for Puppies
and ---> GSD Puppy Primer Tips
Have you heard about Crate Games? Great thing to work on in the house.