Sorry that it seems he may lose both feet. Please post udated pictures as the feet change. Since the tissue is dead, he may not feel much pain, but I would consider his future ability to get around and live normally. There are a few threads about chickens who have lost feet, and who were favorite family pets who lived with considerable assistance. Some people just let them live or not without special consideration. He may not be able to roost or normally mate, and sometimes others will pick on a disabled chicken. But I hope he has a good outcome.
I am not sure if you have mentioned your location, but I would try to prevent this from happening again to another chicken. I have to be careful not to spill water when I am filling bowls in freezing weather inside the coop. I have electric water bowls, and if a chicken steps into one, that can be dangerous.