I know what you mean about the gas/CO detector going off while parked for some time....it's a PIA...
Detectors seem to vary widely as to sensivity....mine is super sentive...just turning on the oven (across the aisle) can set if off.
I installed a toggle switch two inches off the floor in an out of traffic spot that can switch the detector on or off. Stored, summer or winter my trailer is always plugged in, charger on. In the winter a thermostat controlled catalytic heater keeps the inside at 45F...the detector used to go off now and then in the winter (CO)...usually at 4 or 5 AM !!! enough of THAT !
I have newer, beefier springs on my trailer...the only thing I do in the winter or summer is park so the tires
are sitting on wood (not on the grass)