Leave my plugged in over winter in barn ??

I know that part but was wondering about leaving it plugged in and jacks up or down

Winterize the water system and remove anything that might attract mice.

Stabil, yes, if it's a gasoline unit. And then run the engine for a few minutes.

Jacks.....don't care.

Leave the "normal" power connected ONLY if you are sure that your charger/converter has a "float" mode....and you have tested it.
If it does not, leave the 30 amp disconnected,turn the battery disconnect OFF and connect a small automatic tender type battery charger directly to the batteries and plugged into a standard 120 V outlet.

Most people will say to do your annual oil change before putting it to bed.

I personally like to run both the engine and generator for about a half hour once a month or so (but not when it is REALLY cold) but I don't think that is really necessary. I also move it a foot or so at the same time to help prevent flat spots on the tires.

Oh....and if there will be a significant temperature drop during storage, put an extra 5 pounds of air in the tires so that they won't "sag" well below the recommended pressure when the temp goes DOWN.

Being cautious, I wouldn’t leave any RV plugged in over a long period of time just like I disconnect the batteries and shut down my main solar system. Only thing “on” is my trickle solar panel and controller.