I mean electric boilers, heating panels, ranges and car chargers will easily increase peak loads by 15-25 kilowatts per house, that's 2-4x as much as they currently pull. Do that times hundreds of thousands of houses and you see the issue.
The right conclusion is that now they need to buff up the power grid extremely quickly TOO (it needs not take such a long time, some choices like solar or wind are quite quick to install).
Both the consumer endpoints and production endpoints have to change, of course.
As for the billions required for the transition, since when absolute figures make for good decisions? What is required is a comparison with alternatives. And one sure thing is that the cost of a failed transition, of a climate catastrophe, or indirect consequences like wars, are tremendously more expensive.
Politicians tend to make delusional promises which can never happen. Something like this is a long term thing it’s not… stop using gas now!
Governments are trying hard to artificially keep the prices low, but the reality is that the market really really wants people to give up on fossil fuels.