You're overdramatizing. At worst, your 80-year old man would get double or triple the heating bill, then probably demand that to be paid from taxes via subsidies. And that is what people don't want.
Money doesn't create natural gas. If you shut down a pipeline bringing in some amount <x>, and you cannot find a new source to get that amount, somthing has to give, somewhere, you have to use less of the stuff.
You don't need natural gas for housing heating. Buy an electrical heater, pay "exorbitant" electricity bills, get electricity rerouted from other sources (you could still, like, import coal by sea if you don't like nuclear).
True, industrial users can't just start using something else instead of gas in their processes. And if they go out of business, that's production gone, supply chains gone, workplaces gone. Certainly not a good thing, but please – it's not elderly frozen to death by this Christmas.
Do electric heaters magically appear? You do know that stores don't stock enough electric heaters for an entire country to go out and buy them, right? An economic and manufacturing powerhouse like the US couldn't even deal with people buying extra toilet paper. What would happen if everyone in the EU all at once tried to buy electric heaters?
Electric heaters don't go down the sewer shortly after being turned on, and Europe is not embargoed to not be able to import some in the coming months. Surely, the price is going to jump up.
My point being, it's not about individual heaters and house heating. That would be a solvable problem – an expense. However, making that expense is a different thing, since now you'd gotta convince your citizens that they must – not should, but must pay up in taxes for that solution to be enacted. And why? Because some other country got invaded and that pro-o-o-obably might cause something bad in the future for your country.
The other side of the coin being that some things are harder to solve: you can't import on a short notice a replacement for, say, chemical plants that need gas and everything that's connected to them.
> Electric heaters don't go down the sewer shortly after being turned on, and Europe is not embargoed to not be able to import some in the coming months. Surely, the price is going to jump up.
Does this matter? The embargoes are putting up a heavy strain on the world's logistic supply chains. The price of everything that depends on logistics is going up, including things in theory not directly related to not-embargoed electric heaters.
Maybe Americans or Libertarians don't want that, but average people do want that, Hungary's govt has been doing that for years and they have supermajority (70+%) in a free election. Subsidizing utilities is a populist way to get re-elected, but of course it's distorting the market and making everyone else look stupid.
Now in France Macron and Le Pen are looking to do the same as Hungary, handing out meal vouchers and subsidizing utilities. They are polling the voters and that's what the voters want.
Almost no one in Hungary is investing into renewables, since energy prices are frozen to 2017 levels (around a quarter of what it should be on the free market).