Looking for small lot or storage land

Looking for a place for a friend and their family to park their 29ft RV for winter months, with electric hookup possibly (but not mandatory, as they do have a generator). They need to be set up before snowfall and will pay a fee to stay there. Needs to be in the Brampton, Halton region, Caledon, Bolton, or any of the GTA area surrounding basically the semi-country area, for work purposes and to attend their son's treatment. They are very quiet and will be at work most of the day. Any info or help and advice greatly appreciated. Serious inquiries will only be answered.