Drinking on the Train?

So as I plan for the big Easter trip to the UK next year I’ve decided I’ll be using British Rail as my main form of transport. I’ll be flying into Gatwick Airport, visit my long-suffering Mom for a day, then up to the Cotswolds to the Consul and Kentucky, back to my Mom, then on to Portsmouth, back to The Consul, and finally end it all with my Mom and a simple trip back to Gatwick. The question is with all this rail travel, how much should I be drinking on the Train?