The Satmar Rav (Al Hageulah V'al Hatemurah chapter 44) says that it if the Jews told the world they were ready to give up their statehood, the United Nations could certainly find a way to settle the situation without harm to any Jew. Some Jews could be absorbed by other countries, and others could stay and live under whatever new government is formed.

Alternatively, we could put an end to a Jewish state not by taking away the state but by taking away its Jewishness. Right now, the State of Israel has the Law of Return, it has chief rabbis and a rabbinate, it does not recognize marriages between a Jew and a non-Jew, it has certain Shabbos laws, the army serves kosher food, etc. Additionally, there are large religious parties in the Knesset who force their agenda on the government through their voting and coalition power. There are religious settlers who are against giving back land. All these elements allow the Zionist state to claim to be Jewish and act in the name of the Jewish people. If all of religious Jewry were to separate from the state and leave it completely secular, it could be argued that it would no longer be a Jewish state at all and thus not violate halacha. Even if you argue that that would still be Jewish enough to violate the halacha, after a certain amount of Arab population increase and immigration from various countries, not to mention the return of millions of Palestinian refugees, the Jews would be a minority and it would certainly not be considered a Jewish state.