What percentage of living costs is gas normally during winter there? A 40% increase in 3% of your expenses isn't a big deal, but if it's 30% that would really hurt...
My gas heating costs were minimal when I lived in an apartment because it was really well insulated, surrounded by neighbours with similarly well-insulated apartments; I could heat that up with my desktop pc mining ethereum on a 290X back when that was profitable. ;)
As an approximation, heating costs might rise for people less fortunate to close to 30-35% of their income if things end up as bad as I hear them expect.