just a thought and it will take a knowledgeable rv tech to check it
the 'starter' and associated circuits
i hvae NO idea of the starter and wiring your Monaco
but i once had a pace arrow on a P30 chassis
that would drain the starting battery in a couple of days of setting in one place
i traced it to the starter, with the actuator on top, the heavy coil or contacts 'bleed' power internally, where there should not be any drain
the starter was changed several times
before i finally put a disconnect switch on the engine battery
i finally decided, there was another 'modification' done to the circuit someplace by a previous owner.. i never did find it, but i stopped the battery bleed power drain
took less than a minute to turn off or on from the front hatch
and i only use it when stopping for several days
did not worry about over night because it did not drain that fast