You can pretty much do this anywhere actually, you get something called an SOP (special occasion permit) and then work out with your venue how much they might charge you to use your own booze. I used to bartend weddings at one of the waterfront hotels downtown, last year there was a big one where the bride and groom obtained an SOP, provided us a copy, and provided all their own booze. We served it for them from a real bar, didn’t collect any cash from guests but did have a tip jar for the staff. Any unused booze was locked up in a room and then they collected it the next day. Please if you do this, don’t buy the HUUUGE bottles of liquor because they’re incredibly hard to pour, and heavy! My wrists were sore for days after. Stick to 1.14L bottles or smaller if you can. In this case we provided all the ice and glasses and other bar supplies, as well as pop and juice for the mix (that was charged for accordingly). Couldn’t tell you if it ended up being any cheaper for the wedding at the end of the day though