I use DampRid Hanging moisture absorbing bags in my racecar and trailer. They're easy to hang from rollbar tubes. You can watch them fill up with water over time. I've got a few friends who use them now as well. I've had much better luck with the bags over the tubs that they also sell.

Not sure how well they will work in an environment where its constantly frozen though.

Example:
https://www.amazon.com/dp/B00FZDOQEI/ref=twister_B017T17DVQ?_encoding=UTF8&th=1

$7.97 for 3 bags is a cheap experiment. They work great up here in the Pacific Northwest.