Oh I'm so sorry about your injury!

A friend from my club had something similar, although I am not sure how the degrees compare. She was seen at spining with the moon boot! (Dunno if she could fix a cleat to it!) but that was after a while. However, she said she had been too eager to get back on the bike, especially doing some hills, and she paid a heavy price. A year after, she still had to wear the moon boot for part of the day, and her cycling has been seriously curtailed.

It seems like the Achilles is a sensitive area, and that listening to the orthopedist unfortunately seems the only thing to do. You might want to find a doctor who's a cyclist, there's got to be one!