My opinion is that when you should store your RV make sure that all batteries are fully charged then disconnected AT THE NEGAATIVE BATTERY TERMINAL. Don't rely on switches as they may not disconnect EVERYTHING. A fully charged battery in good condition can retain its charge for up to 2 years!
My opinion is that starting an engine and letting it idle for a while does more damage than letting it sit. When you start the engine condensation that has formed on interior surfaces of the engine and exhaust system is exposed to combustion gases and forms acids that are corrosive. If the engine isn't put under load for long enough to evaporate all that moisture the acids remain in the engine oil and exhaust system. If you are going start the engine you should drive it for at least 30 miles.
The generator is another story. The generator consists of a generator and an engine. Onan recommends that for the health of the generator portion of the set it should be started and run at > 1/2 load for 30 min/month. I know that is the recommendation, I've never started my generator in the winter and I have never had any problems in almost 50 years of RVing. My RVs sit from October to May every year!
If it were me, I would charge the batteries, disconnect them, drain the water system and put antifreeze in the p-traps. Lock the doors and go on my 6 month trip and not worry about it!
A much bigger concern is vandalism and theft while in storage! That I would worry about.
2003 34' Georgetown on W20 Workhorse Chassis. UltraRV power mods. Front Sumo Springs, Rear P32 Sumo Springs, UltraRV Track Bar.
1998 Jeep Toad.