Grimm is endless, they are a living curse, sort of, created by a God of Darkness....Fuck I forgot that bit about Dust. Admittedly, Ala Alba won't be able to solve every problem (and they know it), but they are greatly concerned about the Grimm threat, so they would still intervene.
I assume that Grimm can be harmed by magic and thus they aren't much of the challenge for a high-powered character from a high fantasy universe early on, they will wear any magician down within a sheer war of attrition. You can't deal with them in a permanent kind of way, just as you can't kill Salem as she is immortal and will come back even if destroyed completely.
Successfully overriding the above will attract gods' attention back to Remnant, and thus it would cause more problems than it would solve (unless the protagonist have some way to casually kill gods)
You can theoretically evacuate the planet through some kind of interdimensional portal if you do have resources, but that's pretty much it ... and there is still chance that troublesome elements will sneak in with those evacuated. You practically can't take Ozpin with you, as he is cursed or blessed by the gods, and thus serve as a homing beacon for all the things you don't want to follow you.
This is potentially a good way how to pick the plot on though ...