The issue is not people freezing. Wear a sweater and suck it up. Buy an electric heater. There are ways to hack your way through it.
The much larger problem is industrial manufacturing, in clusters like Ludwigshafen, where you have companies like BASF and Benckiser that rely on Russian gas for their refinery operations.
Fertilizers, chemicals, lubricants, etc.
You turn off Russian gas, you turn off the German industrial complex. Literally over night.
And that’s the reason why the German is so cagey about stopping the import of Russian gas. They can’t, because they don’t have an alternative.