I would hate for this to come over as harsh, but I've learned over the years that you go as soon as you can. If you can only go once, it is better for both of you to do it while he can recognize that you are there.
I hope he will get better, and you will visit again. But that should not stop you from going now, if you can.
I travelled to visit a relative's supposed death-bed several times over a couple of years, and then arrived after a late-night drive one morning for a casual visit only to find she had died a couple of hours before. We were at peace with each other, and did not miss an opportunity to visit, although each time we expected to be the last.
A good friend was supposedly stable, but in hospice. I needed to delay the trip for work reasons, and did not get there in time.
My best wishes for you and your family.