We must exercise care in our hermeneutic and let scripture interpret scripture.
In Revelation 7:9: "After this I looked and there before me was a great multitude that no one could count, from every nation, tribe, people and language, standing before the throne and in front of the Lamb. They were wearing white robes and were holding palm branches in their hands."
Israel is included in the qualification "every nation, tribe, people, and language."
Elsewhere, in John 15:5 we read these words: "I am the vine, ye the branches: He that abideth in me, and I in him, the same bringeth forth much fruit: for without me ye can do nothing."
Vine. Branches. Strikingly similar imagery to Romans 11. Jesus does not qualify "he." On the contrary, "Whosoever will, let him take the water of life freely." (Revelation 22:17). Whosover! That means YOU and ME!
Will all Israel - literally, every man, woman, and child of Jewish descent - be saved? Well, other scriptures answer that question. You know the answer. Ezekial 18 comes to mind: "The soul who sins will die", with the context being their trust in lineage rather than accountability for their own actions.
Will Israel - a large number of Jews - be saved last? Very possibly.
The notion, though, that Israel, who as a people, as God's earthly temple, continue to this day in a role designated as special and unique as the cocoon for the earthly coming of our Savior does not pass muster with either reason or Scripture.
Paul said God wasn’t done with the children of Israel, that His covenant with his brethren according to the flesh still stands, and will be fulfilled.
And the fierce overriding demonic hatred we still see demonstrated every day in this world for them tends to confirm it.
I, for one, believe him.