Personally, I think that the archaeological and literary evidence suggests
a multi-lingual Roman-era Palestine, with rich use of Aramaic (perhaps
more heavily in homes and in rural areas) and a wide use/acquaintance with
Greek, plus some acquaintance with Hebrew (esp. among the educated??).
But I note two things at least indirectly relevant to our discussion:
(1) Greek was not introduced by "the conquerors", the Romans, but had been
introduced by Alexander and his successors from 332 BCE, and along with
much else in Greek culture had been readily accepted by many Jews in
Palestine for a long time by the lst cent.; (2) Aramaic also was a
language of a "conqueror" having been introduced under the Persians in
Palestine. So Aramaic testifies, not to Jewish resistance to language
importation, but to an acceptance of it. It is interesting that Bar
Kochba seems to have promoted use of Hebrew on coins as part of his
program of re-judaization of Palestine in his anti-roman revolt.
Larry Hurtado, Religion, Univ. of Manitoba