This is a hard one to call. Your husband seems to be in good shape right now. Forget the statistics. There are many on this board who are Stage IV and living on. My wife is two years from Stage IV diagnosis.
One thing we caregivers have to remember is that the patient has to have something he or she can work towards, goals to achieve. As soon as my wife was able, we took a trip to Scotland last May because she always wanted to go there. Having something to work toward, to live for, gives them strength to move on and feel optimistic. Since this is a financial deal, only you and your husband can assess if the risk is worth it. I tend to say, "Go for your dreams", but I am not in your shoes. How many people of good health make big plans and commitments, and then are suddenly killed by heart attack, car accident. etc? We never know. Follow your heart. Best to you both. Don