I doubt he does this, but imagine Kipchoge attacking all the ultramarathon world records!
On a favorable course, I am almost certain he would break the 50K World record, the 50-miler, and the 100-miler WW if he trained for them. 50K WW is 2:38:43 -- Kipchoge would easily smoke that time. The 50-mile WW is 4:48:21 -- Kipchoge would blow that record out of the water. And the 100-mile WW is 10:51:39 -- if Kipchoge cared to train for that distance, I am pretty confident that that WW would be his as well.
Just my thoughts as he probably only has a few more sub-2:03 marathons left in the tank, so what will he attack next? Hopefully not full retirement.