Maybe reforming is going a bit far as I think there were still quite a few Gladstonian liberals in the party when churchill left, but he and David Lloyd George (coalition Prime Minister 1916-22) were behind the foundations of the welfare state, high taxes for the rich and an experiment involving a nationalised brewery in the town where I grew up. The liberals (later Liberal Democrats) would end up spending most of the next 80 years between the centrist option between Labour and Conservative, then the last 10 moving back towards libertarianism with The Orange Book.

I not an expert either, I did a history course 8 years ago about British working class and left wing history that looked at what churchill did, but it didn't really look at much before 1916.

Wasn't Winston Churchill a Conservative at twenty and a Liberal at forty? He was involved the process of reforming the Liberal party away from being libertarian at the time though.

Is there any evidence he ever said that?