Why not build more garbage incinerators instead? Proven, readily available technology, that can solve immediate danger of not having enough gas for heating.
Unfortunately, EU is biased against it (https://zerowasteeurope.eu/press-release/european-parliament...), maybe it is time to change that stance.
The page you yourself link has a case study in Madeira island where garbage burning uses up 20% of funds for waste management but only deals with 1.4% of waste.
With cheap and easy to roll out Solar and Wind these furnaces are an evolutionary dead end in energy policy.
The argument for waste burning is quite simple: you are left without gas and you substitute what you don't have with what you have, in this case garbage. That doesn't automatically exclude other alternatives, but rather together with them, makes them more viable.