Went to Corning to see the doctor about my frostbit finger this afternoon. He was suitably impressed by my recovery and said that, though I might still lose my nail, I will not have to have any surgery nor do I need to see him again.
Feeling has returned to the middle finger although it's still super sensitive and the other three are virtually normal. The tissues of the middle finger are still new, the doctor said, but they should thicken and toughen up with time. He also said I might recover normal feeling--or I might not. Nerves are tough to predict, but if he were a betting man, normal is the way he would bet.
He also said that there are doctors out there who, upon seeing the original condition of the finger, would have pressed for amputation of part of the finger ASAP. He prefers the "frostbite in January, debraid (amputate) in March/April" method of treatment. He prefers this approach because frostbite--and the recovery from it--is so unpredictable.