If this is a reality concerning the crytek engine I canot image what they could do to comeback.
Several possibilities sprung to mind...
throw money at the problem. Given enough time, and money, they may be able to eventually fix the issues.
Fire Chris Roberts and put a competent manager in charge
Take some time off "development" and work on patching up the engine
Throw band aid fixes at the issues and hope they work well enough to cover over the cracks and prop up the engine.
Ask for the backers support and understanding while they take a couple of years to write a custom engine which CAN handle the game
I daresay that CIG will be able to improve upon the performance when they get back after the holiday, maybe even enough to allow some semblance of testing, but when even CIG devs are stating the engine is operating beyond its limits, you have to figure its only a matter of time before the whole thing breaks. If not now, then the next time there is a major patch or the time after that. There is only so much you can do to prop up a failing engine before all those band aids come back to haunt you.
Given what Clive Johnson has stated, it seems apparent CIG need to stop work on the game and do some serious work with the engine. That doesn't seem to likely so unless CIG get really lucky, it seems doubtful their band aid fixes will do more than mitigate the problems. Still, they might hold out for a year or two.