I can't give you an answer that's specific as to when people feel confident enough that it's worth their while to switch. The carbon levy is escalating by $15 per year to 2030. It will affect people differently. When one person is ready to say, “Okay, I think it's worth my while, given I just commute and don't do long-distance travel”, they may arrive at that decision earlier, especially if there is a provincial incentive program in there.
I can't say what the number has to be to switch everyone over. It will differ among provinces and among people, but it does have to be high enough so that the math works out, so that someone will say, “Okay, it makes sense for me to do the switch. It's more costly for me to use an internal combustion car than it is an electric vehicle,” but the exact price point, especially since it changes every year because it's escalating, is too hard to say. There may be some year-by-year modelling that Environment Canada has about that. It would be quite different between B.C. and Ontario or Quebec and Ontario, but I don't know if they have that.