Stacey,,,,You've got me on a quest now to locate thin mint cookie replacements! Besides the Polars, I've found one called Viscount, these are round white cookie with layer of mint frosting and covered in chocolate, not too bad (got these at Somerfields but they also had them at the weigh & save shop). Also found McVities Mint Chocolate digestives, didn't get them, but they looked interesting.
Enjoy your Polars!!