De
suggestion.
Find yerself a plastic or PVC rectangular, or round piece of 4 inch dia. pipe with threads on the end. like you would find for a clean out line on yer sewer piping.
Shorted in to about a foot in length and get a screw on cap for the threaded end.
Find a convenient place and dig a hole deep enough with a post hole shovel to put that pipe with a house key inside of a zip lock backie inside the pipe, in the ground about a foot down from the top. Fill with anything you want and cover with a large rock or stone that is fairly inconspicuous.
Now you have what I do for times like these....
It works and the heat from the ground keeps it unfrozen..
Glad it all worked out for you guys! What a hassle you went through..