You can update your place with a new map by publishing to roblox. This will overwrite the old map.
Most NBC's have alternate accounts to create more than one game at a time. Which is probably one of the better features of this game. Most online games deny you this ability.
Well, there's only one way.
When you first enter Roblox after your BC ends, your places fall into inactive.
BUT, if you don't log in, they don't get inactive, I use that on my game-creator account, so when I can get BC again I log onto it.