It shouldn't be up to you what happens to it. He can get rid of it and work hard at regaining his balance in sobriety, or he can make an excuse to keep it and/or smoke it and continue his path of destruction.
What's really up to you is how long you want to live like this. You have many years invested and that may be worth some marriage counseling and effort to keep it together...or to cut your losses and leave and reclaim your live in a healthy, peaceful way.
It's up to you all right. What YOU choose to do with your life is up to you. He has already shown you what he chooses to do with is.
Good luck, I know this must be very painful and confusing.