Could you put in a dog door, so he can be in the house or the yard. That has been our solution for years. Once they were house broken, all of our dogs have had the run of the house or yard. While we are usually home most of the time, we have no worry about leaving them for 10 or 12 hours if we have to.
Ours goes though the wall of the house. In the winter we put an entry that looks like a dog house over it. It has a second dog door, so it is kind of like an air lock.
Hmm...interesting!! Not sure we could do that with the way our house is situated on the yard. But thanks for the suggestion anyway.
@Lisa so sorry you and Simba are having a rough time. He is so lucky you came along and rescued him you have done a marvellous job by the sound of it. I don’t have any advice I wish I did.