Hammering the teeth into frozen soil or concrete will break the welds or break your hoe just about every time.
Break out your cutting equipment and square up that mangled steel to remove all the old bottom plate material and weld, then put on a new bucket bottom and reinforced cutting lip. Weld it up with full penetration weld (weld from one side, then grind to solid metal from the other side and weld). The lip usually wraps around the side walls so what is left on yours, needs to come off and the whole thing replaced. You should be able to buy that cutting lip already pre-formed to the side bend.