It's actually 3 liters. So you can bring 3 of the larger bottles. (that's why they normally sell the in-between size at the duty free)
Looks like you can bring in booze and wine. No room for clothes though, but who needs them! "If you are bringing alcohol into Mexico from the U.S., you are allowed to bring up to three liters of liquor or beer and six liters of wine per adult. ... Passengers over 18 years of age are allowed: 10 packs of cigarettes, 25 cigars or 200 grams of tobacco, three liters of liquor or beer, six liters of wine."
You can go to Superama Bonamak by walmart, it is 2 miles away. You can take a taxi from the hotel. It is a big supermarket with wine, beer and liquor. AV. Bonampak SM Mzn 2 LOTE 1-01, Kukulcan Boulevard, Zona Hotelera, 77500 Cancún, Q.R., Mexico
Call me cheap, but I just have one of the bartenders fill me a glass of straight alcohol, whatever I’m drinking, and I take it to the room and put it in the fridge. When I finish it, I get another.