Sorry to hear about your collar bone. I broke my right collarbone in a very similar way (3 pieces) in March and had surgery to put it back together.
FWIW the healing process was super easy for me, other than the initial discomfort and weirdness sleeping. I was back to shifting my car (manual) within a few days, ditched the sling in 3 weeks and was using my arm normally after about 4 weeks. After 5 weeks I went back to the doctor for a checkup, who said I had no strength or mobility issues and that I didn't need PT. I was back deadlifting and squatting in the gym that day.
Hopefully your healing process is as easy, but I think you'll be good to go well before January. :thumbup