Thanks, Dick and Shane. I decided to dive in last night to at least see what I was working with, and of course saw exactly what you saw, Dick. It's a 120mm fan. I'm thinking of using one of those "fan to dryer vent" adapter things and either mounting the assembly to the floor, which will raise the fan several inches, or keep the fan where it is but then lower where the hose mounts into the floor cavity.
I just don't see it being effective in its current setup. First of all, the flange was not sealed to the floor, so much of the air was likely being pulled in from the between the flange and the floor, not the top of the fridge. Doing what I'm suggesting may not make it any better, but it seems worth a shot.
I may also put a stronger fan in there.....the OEM one only pulled a few hundred milliamps, but there are some the same size that pull a few amps, moving quite a bit more air (like
https://www.amazon.com/HIGHFINE-4000...dp/B01LLYQ2VE/).
Dave