You're in luck, I did it last year.
The van was titled as a passenger van in Ontario. It would have qualified as an RV there but I couldn't get it insured in Ontario since it's all private insurers there. When I moved to BC I found I could both have it changed over to RV (motorhome) status AND get insurance. It saved me 40% over regular vehicle insurance and the van is insured for stated value. I did have to sit down and write up an inventory of everything in and on it and price it out at Canadian prices (horrendous btw) since most of the expensive stuff was done stateside!
I tried, like you, to get info from ICBC and 3 or 4 insurance brokers to no avail....no one knew from shit.
I had to have it inspected by the insurance broker, get it weighed on private scales and do up the price costing.
I too have great difficulty finding someone who knew exactly what they were doing. I'm going to PM you the name of the wonderful woman at
a great insurance brokerage firm. I'd put it out in public but I don't want her name out there without permission.