Help- need advice on visiting Vancouver Island in the winter

Actually as you move up to coast to say Parksville there are more parks open all winter, and you might find the rates lower.
All depends on your wants and needs.

Most years if you see any snow, it will be melted by the end of the day. Rarely it will last a couple days. Very rarely (every 10 to 20 years) there will be a heavy wet snow that will last a week or more. If you know that's coming, just plan on sitting tight.