Mint isn't one I consider to be a good indoor specimen. How about making mint ice cubes (like folks do with basil) for your smoothies? I haven't tried it, but it would be worth a test run for you.

FataMorgana

I did over winter some chocolate mint, but it didn't thrive, just barely stayed alive until I could put it outside in the spring. It was in an eight inch pot and I kept it near a lamp and treated it like a houseplant. It got really leggy and I had to keep pruning it back. The leaves stayed quite small and were lacking a bit in essential oils, so I didn't use the prunings for anything. However, it is a way to keep the plant alive for the winter if you have a hard time finding it at local nurseries. You would need a very bright light or window.