Jeff - Back in the day there were aftermarket "defroster fans" offered that you can mount in the cab, directed at the windshield to help with the problem. There are a number of them available, like
this 12V one (you can find 6V ones too) in case you might be interested in going that route. The fan blade is exposed, but it's soft and flexible, making it safe to use in the cab. Some can be mounted to the steering column, while others can be mounted on the dash or from overhead, depending on your preferences. Perhaps this might be an option to consider for your fogging windows?
