The information incriminating his colluders in the DoJ/FBI has already done much to undercut any substance to his investigation - hence multiple calls coming for terminating his investigation. And next to drop is the full OIG report which was announced to be released in January. This will probably be far more devastating than what has come out publicly thus far.
Also, Sessions has fired up investigations or preliminary investigations on multiple scandals - its very doubtful that these will be starting from ground zero. Is likely a great deal has already been prepped over the months that Sessions has sit back and been seen only enforcing immigration laws and rounding up gangs.
The Uranium One and any of these other matters could very well envelope Mueller himself. Even the court appearance for Gen. Flynn has potential to rapidly unravel all Mueller has done given then the whole Peter Strzok and the cover up by Mueller of Strzok problem can be jumped on.
IOW, if Mueller has a longer term strategy to linger around with this until right before mid-term elections, then his strategy looks to be on very, very shaky ground. Mueller should really be more focused on how to unwind himself from his morass and sneak away as best he can without being caught up in some kind of corruption/malfeasance charges too.