Hi Rod
You may want to rethink your dates.
Mid-March to Mid-April here on Canada's East Coast is still in the winter season. We have below freezing temps through-out the day and night for almost all of March. In early April most days will be below freezing and every night will be below 0(C).
When driving we are still prepared for winter conditions that time of year.
RV parks and campgrounds are all closed until mid-May so even if you do visit there will be nowhere to stay with services. Heck our golf courses aren't even open until the end of April or mid-May.
We don't de-winterize our rig until the first weekend in May and even then we have to watch for potential nights below freezing.
March would be an excellent month to visit if you are into snowmobiling, skating or ice fishing. NHL (ice-hockey) playoffs don't start until mid-April.
We would love to welcome you to the East Coast but if you plan to RV June is a much better month.
From local weather tracking:
Daily low temperatures range from -10°C to -3°C, falling below -19°C or exceeding 2°C only one day in ten.