[JRTJH]

Before I disconnected the refrigerator heating element, I'd first plug something else into the outlet and see if it trips the GFI. Then plug the refrigerator (using an extension cord) into another "known GFI outlet in the trailer".... If the "other electrical item" doesn't trip the GFI, and if the refrigerator, when plugged into the bathroom outlet "does trip the GFI" I'd suspect the refrigerator....

On the other hand, if the other item trips the GFI as soon as you reset it, it's probably the refrigerator plug (wet or corroded) or the wiring is loose in that plug.