So what do you think of his death.
When does his death occur? Answer that, then look into the totality of Churchill's life so you can grasp the immediate changes, and you'll begin to fashion a time line.
Killing him in 1915 and then blithely presuming 24 years later there will be a WW2 which resembles the OTL version in anything but the broadest of brushstrokes is lazy thinking on the level of Turtledove.