Great auto insurance question, Polar Man! RVs are not all alike in the eyes of the insurance companies. So it is a good idea to talk to your broker or agent about what is available to you.
RVs can be insured under your auto insurance or as a separate policy called a stand-alone. If they are under your auto insurance you may be required to keep Public Liability and Property Damage (PLPD) all year. Other companies will allow you to drop this coverage and put on just a form of parking insurance, Comprehensive or Specified Perils while the unit is laid up. Not all insurance companies are alike so you need to check this out.
A stand alone policy is usually set up as a package. You cannot use the seasonal lay-up but the extras in the package may be worth it to you. If your package includes personal property then when you do have a break-in or other damage or loss property claim you will not have to separately address your home insurance. Your home insurance will have its own deductible. Another extra can be emergency living expense so if you do have a tree fall on your unit you can go stay in a hotel/motel. This is a nice extra as you would probably want to continue your vacation. A package can also include full glass coverage, emergency towing, fire department charges, and more.
You did mention that your travel is long-term. If you are going to travel out of your country then you need to advise your insurer. Often there is a limit as to how long you would be away without some sort of surcharge.
Do note that when you are away it is a good idea to have someone checking your home. This is especially important during the heating season as some insurers require the property be checked every 48 hours! Again, talk to your insurance agent or broker about your particular insurer and their wordings for keeping your home coverage in place while you are away.
Be sure you have some excess medical insurance in place if you are leaving your province or state. Some of the credit card companies include this as part of their service.
Happy RVing and enjoy your summer!