I'm also planning on moving from London to Vancouver, but I'll be using IEC (working holiday visa) as it seems to give more flexibility at the beginning since you don't need an employer. The downside is you have to pay for your own health insurance for the entire time you're on the working holiday visa.
I was initially planning to move in June 2020 but obviously the pandemic stopped that. They have painlessly extended the date of my visa three times since then and it seems like they're now extending IEC visas again until June 30th 2020.
May I ask how you find the job market in Vancouver compared to London? I'm primarily a front end developer, and to be honest it's almost embarrassing how much I get paid in London. It's one of the only things that make me question if the move is a good idea.