Rav saadya gaon writes explicitly that the Jewish people are a nation only by virtue of its Torah. Umikra malei hu – hayom hazeh bheyaysi li le’am. Today you are for me a nation. In the midbar when they received the Torah. Not in eretz yisroel after the war and division.
The reaction of the gedolei yisroel, notably rav hirsch (few wrote a lot on zionism) was that Judaism is a religion, not a nationality. Rav elchanan discussed it at length in his ikvesa demishicha, as did thw aforementioned bayos hazman, by rav Reuven grozovsky.
They were reform? How dare you accuse the gedolei olam of such a thing?