I am very sorry such bad health has struck.
I think you need to take steps to be put on a heart transplant waiting list. I do not know anything about how to do that but heart doctors/hospitals and even the "Web" should be able to provide guidance.
A defibrillator may be something that can be done soon that will automatically help restart the heart should it stop.
It sounds as though the dilated cardiomyopathy was probably viral. It's certainly a good sign that his LVEF has raised to 27% from 13% in just a few weeks and there is no way to determine if this trend will continue. Ensure he keeps to his medications and don't let him exercise too much. I would certainly consider the Defib implant because if his heart stops, then it will be restarted immediately. If his LVEF continues to improve, then this is just going to be a temporary measure anyway. Now you ask about survival which is understandable and I do sympathise with you. Thanks to new medications, many people with DCM now live normal lives. With his EF at 27% he will still be around in 2 years. I would wait a while before considering a transplant, in case his EF raises again. If it goes above 30% then he is no longer classed as heart failure and 27% is pretty damn close to that. So rather than go through all the risks involved with transplant, and the problems of fighting rejection, I would seriously hold off from that option for now. If his EF doesn't drop again, then I would probably forget that option altogether.