We don't serve alcohol at our parties for this very reason. This forces people to go totally dry against their will or leaves them the only option of bringing their own, and usually they're not keen on sharing. Wait til the last minute to inform people that you are not serving alcohol, so they don't have time to load up coolers to the brim before coming over, then they'll have to bring whatever they have on hand or can find at the last minute..which hopefully won't be much.
Or if you can't trust your friends won't get carried away with the BYOB option, you could just limit alcohol to only wine with dinner...nothing else before or after. Only purchase enough bottles so people can have 1-2 glasses each. Or instead of dinner wine, save the "drink" of the night for later with a dessert spread.
Choose one of the following or give people an option of 1 or 2 things such as: a nice punch with a slight "punch" to it (like champagne ) in a fancy fountain, a wassail bowl, or egg nog with a bit of rum. Just be sure when preparing any of these drinks to only make enough for each guest to have 1 or 2 cups for after dinner.
Allowing a full open bar and expecting people to limit consumption just because you say something won't work. People think holidays mean feelin' good, and don't care if they're buzzed when driving home. Most people don't realize how little alcohol it takes to be legally buzzed if they get pulled over.
If you want to be radical, you can buy a personal sized breathalizer and make people use it. LOL! If they fail or fall in a certain range you can force them to spend the night. :O If they flip out, you can argue that you'll be ultimately responsible and could face arrest if they get in an accident or pulled over after leaving your house buzzed...that is, if you live in a state where the law is such.
One last option could be to assign certain people to be the designated driver for groups of others. This will probably go over like a lead balloon if you do the choosing. But maybe if you e-mail everyone ahead of time and ask certain people to come forward and sacrifice themselves, you might have your solution.
Some cities have sober cabs. Find out if you have this service during the holidays in your area and keep the number on hand and offer it to your tipsy guests