My liver dumps glucose all the time . Type 1 isn't so much insulin deficiency as imbalance of glucagon vs insulin. That's why we all take basal insulin then top up with short acting for meals.
Yes with a meal not a problem but if your liver is still dealing with booze after the meal (likely if I drank a lot) I might expect to need less insulin than normal because my basal insulin is taking glucose out of my blood whilst my liver isn't sending as much out there....