People use most of their energy during non-sunlit times during the winter in Central Europe. It's primarily heating from gas, not electricity usage. This is why they care about Russia who is the only possible gas supplier.
The answer the the question is actually incredibly simple. Switch to electricity. It's more efficient to heat homes burning natural gas at a electricity generating plant and using heat pumps than to burn the gas directly on premise. Gas is not the only suitable fuel for electrical generation, so the monopoly can be broken by switching the power plants to coal/wind/nuclear. This is a fairly capital expensive proposition, but on-site solar heat production in the European winter is pure wishful thinking.