To summarize:
It is not yet clear if this tripping is because of low (near threshold) leakage current, so that random noise causes tripping, or if there is some intermittent event (say a defrost timer) causing much larger leakage current. It is not yet clear if the fault is in the circuit (say because of water ingress) or in the appliance.
The OP might benefit from splitting the loads into multiple circuits, because the ground fault leakage of each appliance and device is cumulative, so the fewer things connected to each GF sensor, the less the chance of a 'nuisance' trip.
If the OP decides to split the loads, it depends upon the specifics of the construction and the local understanding of what a _separate_ structure is to determine if this means a feeder and subpanel are required at each island.
-Jon