Two years ago, I would have laughed at the possibility. But if Kipchoge ran Monza again and they modified it a bit to be within the rules, I actually believe he could break 2 now.
The only two conditions of Monza that made it illegal were the fluids and the pacers.
1. Considering how often he had fluids in Berlin (every 2.5km), it seems that they could legally create a setup where he could get bottles at regular intervals where it would not be an issue.
2. This would be the tricky part. If you select 15-20 sub-60, sub-2:06 Kenyans and pay them enough/train them enough to do a good job, he could have full drafting for at least 30k. Also, if you had a vehicle positioned in the right place, he could draft of the vehicle.
Finally, I think he could do it because he seems to still get better and better each marathon he does. He has 3 remarkable performances since the last sub2 attempt (all conditions considered), and has the zen wizard mental capacity to do it.