McConnell isn't going anywhere. It will be tough for the Pubs to keep the Senate in 2020, so McConnell is not going to lose in a primary. The chance of losing an open Senate seat in a general election is much greater than if an incumbent is running. The pubs will be playing defense everywhere in 2020 on the Senate side. The only pick up at the moment is Alabama.
It is time to disabuse yourself of some fantasy.