If my calculations are correct, only ~21% of gas used in europe is used for electricity, so halving the dependency. If combined power and heat plants can't be shut down (because they can't be replaced that based and still need to produce heat), this results in 12.6% of gas used only in electricity only power plants. The latter isn't really that useful.

Source for all numbers: https://ec.europa.eu/eurostat/cache/sankey/energy/sankey.htm...

16.03e6 TJ gas total

2.03e6 TJ used for electricity only

2.30e6 TJ used for electricity & heat, 60% of resulting (usable) energy is electricity

-> 1.37TJ

-> 3.40TJ of gas used for electricity, around 21%