Judah's wife was a Canaanite, he married her because her family had great wealth. Two of his half-Canaanite sons were killed directly by God, the last continued on but was not seen as legitimate, as his sons did not carry the inheritance of Judah. Tamara was not a Canaanite, but an Aramaean, a "Shemite" like the Israelites, it was her who was found to be honourable by God, and her two sons carried the inheritance of Judah. This means there were Judeans who were descended from the Canaanite wife, and Judeans who were descended from Tamara. Many of the Israelite progenitors are recorded as doing something sinful and repenting of it. The most noble of the progenitors was Joseph, and his sons were Ephraim and Manasseh. The area of "Israel" was conquered by Assyrians, many captives were taken by the Assyrians, but many of the inhabitants would have fled via the expansive maritime trade routes to the various colonies in North Africa & Europe, as well as to the Mediterranean countries, whom had no problem with their assimilation. Also Josephus records that Herod destroyed the Judean genealogical records, which contradicts the Jewish claim that the Romans did it when they invaded & sacked Jerusalem. But according to Josephus, Herod burned them to hide his illegitimacy as king, because he was half Edomite. Edomites were conquered and assimilated into Judean societies, as long as they superficially got a circumcision and superficially acted like the actual Judahites. But it's worth remembering that Esau intermarried with Canaanites & then Ishmaelites, but they would have been of mostly Canaanite stock over the generations.