Fyi, these estimates almost always wildly over-estimate the amount of power needed to electrify everything. When carefully calculated, it's much less because fossil fuel infrastructure is just so damned inefficient. You burn most of it up just getting it from the ground to the engine or furnace, which themselves are wildly inefficient compared to electric versions. The book Electrify! has a detailed breakdown. It's America-centric, but applies to Canada well enough.
With better transmission lines there's also huge rooms for load sharing efficiency improvements, but I would still argue that we should be vastly overbuilding electricity production. Everything in society is cheaper and easier when energy prices are lower, and if we don't have the same carbon cost to that production there's no reason not to spend money there as a giant subsidy to everyone.
Yes, and especially with solar and wind, it's so cheap, you overbuild so it covers more baseload, and when you have excess, you can create whole new industries like Hydrogen production that can ramp up quickly and make good use of it.
Predictable, reliable excess energy on the grid, even if it's transient, oughta be useful for something. Water hydrolysis is as good a use as any. Manufacturing methane from captured CO2. Water purification from ocean water. something.
For sure. There are countless new industries that could pop up if there was transient super-cheap energy. Basically, anything that could be totally automated and is energy limited. Some things require more predictability than others, but there are lots of opportunities. And in the end, you get a more stable grid with less need for storage or "peaking" plants. "Make hay while the sun shines."
In general, we should be overbuilding because we are parked right North of the second largest consumer of electricity in the world and electricity prices in a lot of US states is crazy expensive.