If the result comes close to the polling, the SPD has many options:
GroKo 46% vs 44% for the opposition
Traffic light: 52% vs 38%
Red-Green-Red: 47% vs 43%

However, if CDU does a bit worse GroKo is out and if Linke misses 5% Red-Green-Red is out. Traffic lights is the most stable combination numbers wise, but might be less stable considering political content. Kenya consisting of the three largest parties is stale numbers wise, but I think would have lots of internal tension.

Thanks for the write-up, we will see tomorrow!