Hi there! I wanted to answer the question you asked in my Christmas town thread, but I know that certain topics are off-limits on the boards, in particular anything related to the Power Saves device, so I figured rather than risk being blocked by responding directly in the thread I would VM you instead. That is actually how I am able to have as many towns as I do - with Power Saves I am able to keep many backups of all different towns using only a single cartridge. It's definitely taken my New Leaf experience up to a whole new level, and it has saved me the expense of buying multiple cartridges of the game for sure!