I'd do as Kynvuu has suggested. Change both names of your map in Map Maker, the name and display name. This will save an exact copy of your map but under a different name and you will be able to access it in Map Maker later on. If you'd like, you can still make a backup copy of the map with it's original name first and then change the names, that way you still have a backup if something goes wrong (which it shouldn't but FeralHeart can be a fluffbutt sometimes).