They could ration more initially say in 3 months if they go that way then and ease certain issues as soon as possible lowering the threshold to minimum rationing over 3 - 8 months. +0.5 GWe
In the winter they could put people on amber alerts sometime so that everyone checks for anything which can be switched off or turned to eco mode that's ok to do so. +0.6GWe during spikes and good aluminium and coal use saving.
They could export some energy demanding Industry activities in the winter to somewhere with better green energy reserve lye. 1.2GWe extra in winter.
To earn money with all the excess energy in some of the year from extra efforts could be used to bolster some industries during such times.
To save on petrol they could temporary subsidise public transport and after 2 years replace the policy with a more modern dynamic green transport policy.
In 2 years Aluminium Ion cells will be in or near mass commercialisation so over 8 years aluminum Air plants can be phased out and replaced with this battery technology and when this technology blasts off electric cars can become far more viable for more people and the world will be truly coming out of the industrial dark ages.
Instead of buying batteries for electric cars more could be used to back up the grid and people could purchase smart grid batteries saving about 6 euros a month in energy bills costing about 170 euros, 135 subsidised. 500,000 people doing this extra = 0.5 GWe 1 million = 1 GWe and if that's coupled with super capacitors it can offer a bit more extra during some degree of spiking.
Good quality warm clothing could be subsidised so less extra heating is required. +0.2 GWe during spikes.
Germany could invest in more super computing so that they can do more when there's a good supply of electric and less when there's less which won't be much of an issue after 2 more years. 0.2Gwe
Germany could clamp down on cannabis growing during the winter and turn a bit more of a blind eye to reasonable quality imports during such times. 0.2 Gwe during spikes
Germany could promote mini pcs and more low watt compute solutions in the market 0.4GWe
They could encourage people more to use apps which help them be more energy efficient and ethical 0.1 Gwe
They could probably convince some more of their companies to improve logistics energy efficiency and lower fuel use a bit in that regard. 0.3 GWe
Totalling less petrol use and 3.5 - 6 GWe electricity extra minimising high demand in low supply times and minimising the pinch Germany would have to take pulling away from the Russian oil contract whilst keeping things go in the green direction with a little C02 increase although only really during times of high demand and low supply which will have been mitigated by the efforts.
Adding up both my sets of measures Germany could have over the next 2 years an extra 12 - 30GWe industry of peak use low demand reserve enough to shift every OAP in germany to electric heating. also good excess in low use times high demand times for industry to capitalise on it.