As you said it yourself, there is not going to be enough energy for everyone.
Rationing energy will lead to people not heating their homes as the other possibility (scenario 1) is the destruction (not monetary) of Industries that can't just stop working for a year or two. Germany is an exporting nation, it would be fucked. In this scenario Germany would hit recess so hard it would stop supporting Ukraine on the spot.
So its going to be people not having gas for heating so that the nation as a whole can try to exist down the line in the same level of comfort they are used right now (scenario 2).
This is not Croatia that makes its money from tourism where if they take a hit for a year, tourism doesn't suddenly stops being an option. Germany without Siemens, Bosch, BMW, VW, Mercedes, Kraus Maffei etc. is ... worse off than Spain or Portugal.
So the actual way of doing it is (scenario 3 = current plan), still getting gas from Russia, coming up with plans to off set them within a year, supporting Ukraine with weapons etc. You really think Russia is stopping the war because they loose money from Germany? They aren't paying their soldiers as of now, they will just continue.