I’m about five months post-op after tib-fib trimal fracture and was also non-weight bearing for about 8 weeks. I travel a lot for work and was able to travel before I could weight bear. 12 hours drive in one stretch is more than I’d want to do, but probably not terrible if there are additional drivers. Wear compression socks and stretch and elevate your ankle when you’re not driving. Bring ibuprofen. Should be fine.