Elderly and poor will be hurt the most, that is true. If the source I linked to is correct, it claims it would only impact 10% of demand. While I don't know what that would look like in practice. I sincerely hope (and expect) that it would not lead to anyone, including the vulnerable, freezing to death, or getting seriously ill.
People in privileged positions often talk about making small sacrifices to fulfil some grand end. It always impacts the least privileged the most, whether that be through poverty or something like old age. We've just had 2 years of it with the pandemic, and now we're seeing it with war, and you've extended it to the boycott of a company providing a very necessary resource.
> it would only impact 10% of demand
What would it do to prices? My advice to you is to try imagining what it's like to run out of money before the end of the month and have to freeze your way to the next, then as an elderly person. The path to hell is paved with good intentions.
> While a complete loss of Russian gas imports, currently making up almost half of Germany’s gas needs, “will lead to bottlenecks in some European countries”, supply shortages “would be limited to up to 10% of demand”.
[0] https://www.theguardian.com/world/2022/feb/23/europe-winter-...