First, do you imply "till his very death"? Because if not, he can repent and come back to the Church any time. In fact, we don't know if true repentance happens at death, for it may not be visible to anyone but Christ.
Then there is the question of full cooperation of the will. Does he know and understand the dogma? Does he seek to reconcile his views with the views of the Church? Is he grieving over his dissent?
Then, -- as you perhaps know, but I post for the general readership, -- not everything the Church teaches is dogma. Many aspects of the Church, often the most visible ones, are "disciplines", not dogmas. A good example is celibacy of the priests in the Roman Rite.
But finally, one who knowingly and willingly resist any dogma of the Church to the end cannot be saved, no.
The Last Judgment
Hans Memling
Merry Christmas!