So sorry you fell on that ice. Sorry you hate winter (considering your situation I understand... even if it is my favorite season;-) Which hand is it?

Your idea to study theory is a really good one. No wrist involved! Writting lyrics about how pissed you are at being laid up, could be a great way make lemonade out of crappy situation. Both of these will provide a great way to keep in the game until that @#!% cast is cast out.

Your callus building will not be as painful as it was when you started. That cast will come off soon and you will charge back into playing without a lot of difficulty. You dont' play like beginner any more. Beginners finger pain is usually as much a result of playing with a death grip as the lack of calluses. Your will return quickly.

Also, you know how to finger chords and your muscle memory won't forget that fast. A few weeks without practice isn't going to set you back that much. Even if you do chomp at the bit until the damn thing is gone. At this point I expect you will rebound quickly once "that damn cast" is gone.

I went for years without playing guitar due to chronic pain in my forearms. Finally I was able to start playing and to my surprise my muscle memory remembered most every thing. Not all at once.. but surprisingly quick, I was back playing my original compositions which involve a lot of weird jazz chords. I had written lead sheets with chord names. But I didn't recognize any of those jazz chords on paper! However, I found that if I practiced I was amazed how fast my fingers found them by feel. I have way more faith in my muscle memory than in the organ in my skull. I heard an interview with Kieth Richards (rated one of the best rock guitarist of all time) where the interviewer asked "How do you remember all those songs?".Kieth came right back and said with a big smile "I dont... My fingers do" He was talking about muscle memory.

Your have a good plan to help you through the nest few weeks. Trust returning to your instrument won't be as bad as you think. You will get those calluses back quicker than when you started. What your brain doesn't remember, your muscle memory will. In my opinion Muscle Memory is the greatest force in playing music competently. Yours won't abandon you just because Winter smacked you down!