At first I was worried that we wouldn't be able to keep him down, but he really couldn't do much and it was all we could do to get him outside and back for a potty break. It was like 10 degrees out, so that was a lot of fun for all of us.
After a week, he was still hopping on three legs and not wanting to get out of bed. We returned to the vet and got x-rays to rule out a fracture. The second vet also thought it looked like a soft tissue injury so we got some new pain pills and went home for another week of laying low.
A full two weeks after the injury, he was walking pretty much normally - occasionally hobbling just a bit. By three weeks, he seemed to be 100%.
For posterity's sake, here's a video of how pitiful the little guy was. There's a treat on the floor a few feet away -- which he normally will do anything for -- and he couldn't/wouldn't go get it: