All of that supply comes under long term contracts.

A lot of Europe's gas comes from Russia, which has enough reserves and production capacity to expand, and has enough spare capacity in the pipelines to Europe (and is busy building new ones). Peak gas will strike at some point, but there are no real risks of short term disruptions. Italy and Spain also import from Algeria, both by pipe (Italy for now, Sapin soon) and by LNG, as well as from various places by LNG (Nigeria, Qatar, Trinidad)

Also France uses very little gas for power production, so demand is residential and industrial and thus quite predictable. The other big economies use a lot more gas in the power sector - it's replacing coal these days - also for carbon emission reasons.

(Note that the UK is connected to the European grid through only one single pipeline which does not have a very large capacity)

In the long run, we're all dead. John Maynard Keynes