Baptism of Desire itself is God's Providence for His elect....
I wonder why you do not accept that if God can arrange for you to have been baptized, it is by the very same Providence He can arrange for anyone else who desires or is willing to be baptized. If one is going to do it, almighty God will give one the time to do it, and the water for doing it, and the minister for doing it - the same as He did for your baptism. There is nothing that is unforeseen to God, whether that be an accident or anything else.
Do you not accept that it is God Who Provided the sacrament to all people since the promulgation of the Gospel who've ever been baptized?
A BOD, as Trent says, is justification by faith alone, not Divine Providence, certainly not Divine Providence for His elect.
"There is no one about to die in the state of justification whom God cannot secure Baptism for, and indeed, Baptism of Water".
You will need to name only one instance or condition where God could not provide the sacrament to one who sincerely desires it before I would consider salvation via a BOD as being possible.