I know this is probably a common topic. For me, I’m not sure if it’s a “trope” or just totally misinformed writing, but it’s how many authors approach alcoholism. Some examples are Girl on the Train and The House Across the Lake, among HUNDREDS. If anyone else here has struggled with alcoholism, you know it’s not just "i woke up after downing an entire bottle of whiskey but was able to shower, down a cup of coffee, and solve a murder. "
Getting on the train and cracking open a can of something alcoholic is pretty standard in the UK. A lot of people use the time on the train to pre-drink before going out for the evening.
Canned pre mixed drinks are easy to find in most supermarkets.