I've done 3 fresh restarts (with the released version) so far and hes gone to a different place each time, it has always been a settlement though, he never wandered off into oblivion or just went aimlessly. I am not using pack attack (never meshed well with sim settlements for me, I assume because of the heavy scripting.). I think the only mod I have that has wandering NPCs would be tales from the commonwealth, I guess we are the minuteman might add some patrols but I'm not sure if they even kick in with no minuteman settlements. Other mods are fusion city, outcasts and remnants, project Valkyrie, unique npcs (creatures and monsters) everything else is clothing, looks, settlement object addons.