Injured and fed up

I fractured a bone in my wrist 6 weeks ago. It was originally diagnosed as a minor triquetral fracture and I continued to work out focussing mainly on cardio and substituting wrist weights for dumbbells. I've now been diagnosed with a scaphoid fracture and am immobilised and in plaster for a further six weeks, pretty much unable to work out at all.

Anyone have any suggestions on how to keep active, especially as we head into winter?