Not the worst idea.
I want one to put my bike back together in Burgos. Was going to post it home along with a few other things, but a tiny one would mean I wouldn't have to bother...
Be wary, I had a multi tool taken off me at customs because it could be used to un screw the seats from the plane (it was once done apparently) - I guess a torque wrench could also be used for that.
Are you going to carry it with you?
At those weights I guess it's not out of the question.