For comparison's sake, lets look at Andre the Giant:
From his Wikipedia:
"Roussimoff has been unofficially crowned "The Greatest Drunk on Earth"[74] for once consuming 119 12-US-fluid-ounce (350 ml) beers (over 41 litres) in 6 hours.[75] On an episode of WWE's Legends of Wrestling, Mike Graham said André once drank 156, 16-US-fluid-ounce (470 ml) beers in one sitting, which was confirmed by Dusty Rhodes. In her autobiography, The Fabulous Moolah writes that André drank 127 beers in a Reading, Pennsylvania, hotel bar and later passed out in the lobby. The staff could not move him and had to leave him there until the giant awoke from his slumber."
Now, obviously Wade Boggs is no Andre the Giant, but given the prodigious levels of alcoholism that some people can reach, why is 10 gallons of beer so far fetched, particularly if it is of the light variety?
On a side note, Boggs ate pancakes before every baseball game.