4 pints usually becomes 5 becomes 6 becomes......
and the more you have the more capable you will feel for the cycle home but in reality you'll be more INcapable.
19k is a fair distance. It will probably be dark. What if you caused a car to crash and innocent people were killed perhaps including children. They're lives and yours ruined.
Sorry to be so serious but it really would be a stupid, irresponsible thing to do. Take a taxi, arrange for someone to pick you up, take a sleeping bag and sleep in the bushes, get a bed and breakfast, or else just don't go.