Cache is NOT at the posted coordinates. Don't even try to look there!
There are two ways to obtain the coordinates to this mystery cache. The first way is to solve this complicated puzzle:
The second way to obtain the coordinates to this mystery cache is to find PezGremlin at an event (any event will do; CITOs and Megas included) and say the special password:
"Hey PezGremlin, Ice Bank Mice Elf!"
He will then gladly give you the final coordinates. It is recommended you also take a selfie with PezGremlin at this time to include in your found log. (No, the picture isn't a requirement, but where's the fun in that?)
That's it. This puzzle can be as easy or hard as you want to make it.
Oh, and then you'll have to find the cache too. Happy Hunting!