I suppose another way of interpreting the scriptures (in a preterist/convenantal sense) is just to interpret words like eternal and everlasting to mean "a long time". IOW if we interpret "everlasting" to mean for several generations, then that solves the problem of the everlasting covenant in regard to the Land of Canaan and other "everlasting" Covenants promised to the Jews.
Of course then we have to wonder what it means when Jesus promises us everlasting or eternal life. Does that mean it is conditional or that it will only last for a long time?
It is interesting to note that the Land of Canaan has never really been possessed by the Christians, but that Jews have inhabited that land since the time of Joshua. They are now once again not only in posession of Canaan, but in control of the Land which God promised them. I don't see that the Church (which has supposedly replaced Israel in regard to the covenants) has any ownership interest in Canaan (other than perhaps a few disputed holy spots).
I would think that if the covenant promises to Israel were now applicable to the church, then the Church would have posession of the Holy Land. It doesn't. It never really did. So what does that mean?
That reminds me of an objection to the song "Amazing Grace" that one of the pastors of my youth had. (He was a calvinist, independent baptist, btw.)
He didn't like the line "when we've been there 10000 years, bright shining as the sun, we've no less days to sing God's praise than when we first begun."
As he read it, the song was limiting eternity to 20,000 years (2 X 10,000). He had a point. (His rewording had logical problems, too, though I'll not go into them.)
Conditional eternity, like conditional promises, is not "building your house on a rock."