I absolutely love this! And the maze idea makes it even better! I wish I had you for an aunt! Or that I had siblings, so I could be 'that aunt'. Really, this was a fantastic idea. And the boot incident does mean your gifts are very appropriate!
I'm Canadian too, but we don't that THAT much snow in my area. I'm curious what province you are in. (I'm southern Ontario. More people, less snow.)
For the next one, maybe put the key in a block of ice? If they come with keys that is!