Make sure you drain the water heater, and use antifreeze in the lines. As far as the solar panel is concerned, you shouldn't have to do anything, really. I would confirm with the manufacturer, but if its attached to the roof, you should be fine. Again....confirm this to be sure.
Do call the factory, they are a wealth of information. We live on the SF Bay Area and really dont do much of anything as we use it year round. If you live in freezing temperatures you want to winterize and follow the directions. We belong to a Facebook group Outdoors RV Owners group. Wealth of info as well.
I would talk to a representative from a RV sales and service company
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