Tony

Jay makes a good point about the heavy pruning. It's not really good to do any thing too drastic to a tree that's having problems already.

"Should I shelter them from rain and let them dry out a bit?"

I would definitely keep this one in a spot sheltered from the rain so 'you' can decide when it gets water, or...........

Just had a thought. I think the best thing to do is to take it out of the pot without breaking the rootball apart and plant it in the garden or flower bed for the winter. Cut off encircling roots and tease out roots at the edge of the rootball but other than that leave it intact. It will drain better in the open soil than in a pot. You may even want to leave there for a season to regain its health.

"I've read that some remove and replace the top layer of soil this time of year, do you think that would help until I can repot in spring?"

I don't think that would help in this situation. I suspect all of the feeder roots are deeper in the pot than that.

Tony