I know about the Q Gospel, but I understand it's primarily hypothetical; no known copies exist.
I suppose comparative vernacular could be used, but the time frames are too close for that to be reliable, since elders will be using their vernacular, while young people will be using theirs, regardless of the exact year, and both vernaculars will be somewhat distinct.
We known nothing of Aramaic Judaism in Galilee, and have no writing at all to compare too.
What we do know is that tehre was very little Aramaic transliterations to state an Aramiac origin in Galilee by eyewitnesses.
By our best accounts, these sayings, were collections in Hellenistic communities in Koine believed to have been form. But once again, these have no historical tie to Galilee. We can only state the community compiling the gospel thought it went back to Galilee.
These authors and Q and Thomas, were far removed from any actual event or person, so I place very little faith. As a matter of fact, if this was written closer to his death, we would expect more historical accuracy, and as there is, we have very little that can be stated with any certainty.