You DO keep a spare set keys hidden on the motorhome - but outside the motorhome's interior - don't you?? I've learned long ago over many vehicles to always do that.
Regarding the refrigerator not getting turned back on after shutting off power to gas up - I velcro'd a voltmeter right on the cab dash that shows how much voltage is on the coach's 12 volt system. If it shows zero when we're back on the road after gassing up - then oops -> I forget to turn the coach's 12 volt system master switch back on.
The voltmeter in the cab also indicates whether he engine alternator's output is getting to the coach batteries as it should. I've had the interconnect solenoid for this fail once in the past such that the batteries were not getting charged back up while driving between camp sites ... the dash voltmeter prevents this surprise from happening. (The dash meter shows around 12.7 volts on-down if just the coach batteries our powering the RV system, but it shows around 13.5 volts on-up if the engine alternator's output is properly getting to the coach's 12 volt system - and hence to coach batteries for charging - when traveling.)
2005 E450 Itasca 24V Class C