Has there been a similar situation? Can we use data from 1979 oil crisis?
There were several situations that were somewhat similar. Oil crisis of 1979 is good example of similar shock (although OPEC only produced about 7% of world oil whereas Russia produced last year 13% of world natural gas - see the link in next paragraph for sources), although of course history never repeats itself it just rhymes.
This being said Hamilton (one of the top energy economists) argues that 1979 oil crisis would be more or less valid comparison (see his Princeton Bendheim Center for Finance lecture).
However, one of my past professors, Benjamin Moll with coauthors wrote quite a good paper on this exact topic, and his numerical simulations showed that the impact on Germany would be only about the size of COVID-19 recession (about 1-3% of German GDP). From all the large EU economies (e.g. France, Spain, Italy), Germany is the most exposed to Russian gas. Thus, other large economies should fare better, and only small very exposed countries like Slovakia are expected to fare significantly worse. This is shown to hold even if elasticity of substitution for natural gas is very low in the short run.
This being said, a problem with numerical simulation is that they always have to make a host of assumptions. For example, politicians might not respond to the issue optimally, or maybe elasticity of substitution for many firms in the economy might happen to be not just close to but actually zero because of complex production chains where everyone has to stop just because one company downstream had to stop completely.
But it is fair to say the macro effects would likely be something in between the 1979 oil crisis in the US (which was milder) and something slightly less worse than the COVID-19 recession where many countries contracted by something in the ballpark of 4.5% (average for OECD members).