Mint has always overwintered for me in pots just fine.

Has it overwintered and continued to produce during the winter? I've had it live in pots, but not stay green.

I lost a lot of mine this past winter. The ones in the huge tufa pots made it okay, but died back over the winter. The ones I lost were in smaller 2 to 5 gallon plastic pots. I think the reason was that after a week of temperatures in the 70's, it dropped to 6 degrees overnight. I lost a lot of other things, too. Not at all typical for us.

I've had spearmint in a 14 or so inch tub for years, some winters it dies back others it doesn't, it even came through a winter where the the temperature dipped to -4 degrees F. It's as tough as nails here.

My mint pots have always lived over. Occasionally, they get too scruffy, and I start over, but they never actually die from the winter conditions.