Flying for Thanksgiving? Don't forget cocktail mixings

in flight cocktail airlines drinks
Stephen Swintek | Getty Images

Winter storms already have airlines announcing snow-related delays and cancellations for Thanksgiving travelers. Add in long security lines, cranky passengers, and limited legroom—never mind the prospect of family holiday drama at the other end of the trip. Need a drink, yet?

Mid-air, $8 buys the ability to cobble together a simple cocktail with a mini bottle of booze and whatever free mixers are on hand. Think vodka and soda, rum and cola, a spiked coffee. In-airport drinks are even pricier. But bartenders say it's easy to get a better cocktail for less to enjoy during travel delays. Transportation Security Administration carry-on rules have no beef with alcohol, provided you're of legal drinking age, the bottles are 3.4 ounces or less, and the stash fits in the allowed quart-sized plastic bag. In air, however, Federal Aviation Administration rules require flight attendants serve all alcoholic beverages.

Read MoreWatch out! 11 ways retailers get you to overspend

"It's something I just learned recently," said Seth Sempere, bar manager for Spur Gastropub in Seattle. His travel stash for a recent 16-hour trip to Italy included minis of bourbon, angostura bitters and a bit of maple syrup, enough to make several Old Fashioned cocktails.

Bringing your own minis can be far cheaper. The same 1.7-ounce nip that airlines charge $8 for is more commonly in the $2 to $5 range at local liquor stores, and bottles on the higher end of that range are usually craft or niche brands. "Two nips of whiskey and one nip of vermouth makes two Manhattans," Sempere said.

Read MoreFor holiday budgets, parties are worse than presents

Or you could spend nothing. Mix your favorite cocktail at home with spirits you already own and then decant it into a travel-sized container, said Josh Mazza co-owner of The Gilroy and JBird Cocktails in New York City, who does just that every time he flies. (Stick to spirit-dominant cocktails rather than those calling for add-ins that require refrigeration, like citrus juice or egg white.)

Travelers determined not to check a bag may need to prioritize their selections. "Don't make it so you're not even able to bring shampoo because you have so many little bottles," said Anna Mitchell, a bartender with Capa Restaurant at the Four Seasons Hotel Orlando. In that case, save your space for mixers that aren't on the airline's menu. Then you can buy gin on board for a Negroni, whiskey for a Manhattan, vodka for a martini or a split of sparkling wine for a French 75.

Read MoreMistakes that are ruining your homemade cocktails

Post-security, you can even grab a few other items from food court condiment stations or airline lounges to fancy up in flight drinks, said Christopher James, head bartender at Jockey Hollow Bar & Kitchen in Morristown, N.J. Salt and pepper packets or cocktail sauce can spice up a basic airline Bloody Mary; sugar packets or honey and lemon or lime wedges work in recipes as varied as an old- fashioned, a daiquiri or a sidecar.

"Generally, I'd say keep it simple," Mitchell said. "Stick to max, three spirits. Anything beyond that, your neighbor is going to be looking at you a little crazy." That also limits your need to precisely measure amid turbulence and armrest-hogging seatmates.

Correction: This version was updated to correct the FAA's alcohol regulations.