To get rid of moisture I now remove the lid annually and let it bake in the sun for a couple days to thoroughly dry it out, turning and draining it after it thaws. (I put a black garbage bag over it to get it really hot). I bought a 2.5" rigid insulation slab (styrofoam) from the hardware store to place on top of the freezer while I do that -- 24" wide just barely covers ours (ours works fine with the lid electrical removed, but check your schematic).

Careful: the hinge springs are very powerful - I alternate 2 bar clamps to gradually compress or release each one at a time (with a block of wood at the front to keep the lid from sliding towards the back).

I've removed the pieces of fibreglass batt insulation from inside our lid (they always got sodden) and just rely on the rigid styrofoam inside the lid. I also applied silicone caulk to all exposed electrical connections inside the lid to try and prevent moisture from tripping the GFI breaker. It seems to be working (no GFI trips for years now).