Flying in and out of the Balkans for Best of Adriatic tour

Dubrovnik doesn't have rail service, so you'd need to start with a bus. I don't know where in the US is home for you, so I can't look at options on Rome2Rio.com, but it's worth trying that, just to see whether there's a possibility you haven't considered.

Flight routings often show up as options only when all segments are on airlines that are part of the same partnership (like Delta+Air France or United+Lufthansa, etc.) It's conceivable you could put together separate flights that would--on paper--be better. However, that is a very risky thing to do: If your initial flight is delayed and you miss Leg 2, you'll have to buy a last-minute one-way ticket home, probably at a very high cost indeed.

It seems that United has a non-stop from Dubrovnik to Newark on Tuesday, Thursday, Saturday and Sunday. I suspect that may not be a year-round option, but it might be flying at the time you need. That might be your best bet for putting together a one-stop trip home.

I'd use something like Google Flights with origin=Dubrovnik and destination = your home airport and see what comes up. Have you done that, or have you just checked one airline's website?

Thanks for the info. We have tried Expedia to book the flights, as well as Delta’s own site, but will look into Google flights and Rome to Rio. By the way, our home airport is Minneapolis/St. Paul.

1 You might look at departing from Podgorica as it different connections and its a great day trip to get there.
2 When this happens to me I try and make Lemonade by spending a few days in the connection location.
3 A connection I have done several times is Dubrovnik to Podgorica to Budapest and to home.
4 The stops in Montenegro and Budapest made the trip even better; but there are a lot of choices if you can add 2 or 3 days on to your vacation
5 From DBV you get a discount flight then pick up an open jaw for the rest of your return: options in the spring include Madrid, Barcelona, Vienna, London, Istanbul, Rome (all within about 2 hours except maybe London).
6 From Podgorica your options include Budapest, Milan, Rome, Warsaw (but a lot of the discount airlines will not put up the Spring schedule for another month or so)

Check Zagreb, which is not a hard slog from Dubrovnik.

I flew back to the US from Zagreb in 2015. It was a one-stop (in Europe) trip to Washington-Dulles. However, I don't see any advantage to including Zagreb in a routing from Dubrovnik to the US. It appears that ground transportation between Dubrovnik and Zagreb takes 9 hours or more. Switching from bus to train in Split doesn't seem to save any time. You'd really need to fly between the two Croatian cities, in which case why limit yourself to one particular connection point, especially one that probably won't offer direct-flight options back to your home airport?

Dubrovnik to Podgorica is a quicker trip by bus than to Zagreb--and I do like Montenegro--but I'd be flying out of Dubrovnik to get home if that was my last destination.

Do you have any wiggle room, or are you required to depart the day the tour ends/the day after?
When I suggested Zagreb, it is because you can take a cheap Croatia Air flight and I know Zagreb has a higher chance of getting a one-stop flight home. Best to check all possible options, but we need to know how much time you have.

I took a Vueling Air flight to Rome from Dubrovnik. It was inexpensive, quick, and put me in a position for lots of flight options if I wanted them.

Dubrovnik has an active airport. Croatia airlines and others use it.
Zagreb is now a major new terminal with hopes tp be a hub. Croatia Airlines, Lufthansa and Ryanair use it.
I flew into Zagreb via Frankfurt on Lufthansa then Croatia Airlines from Vancouver as usual in September. Flights to and from non Schengen counties outside the EU bcustoms/border zone, such as Croatia and Canada and the US can use a wing of Frankfurt airport and never go through passport or customs at all. You are not in Germany. New and odd, but it works.

Subrovnik is a long way by bus. A quick flight up to Zagreb would be more pleasant end to your trip. Zagreb is great now too.

Charter airlines of all sizes will start again n the spring, but may not be reliable due to may factors. Use main carriers.

Trains across Europe continue to have uses, A bus in Croatia is my favourite mode of travel. Just had to do a dogleg to Vienna to get to Germany due to limited rail service and even then I got misdirected at Nuremberg and was an hour late. Booking on the trains seems to have problems if Croatia is involved.

I am flying out of Frankfurt on Monday, but a friend is driving me to the airport. Better safe than sorry.

It is possible Croatia will be part of the Schengen area by next spring.

We are on this tour in May and our home airport is also MSP. I booked flights on Delta/Air France (Hop), flying MSP-CDG-LJU on the outbound and DBV-CDG-MSP on the way home. The flights from CDG to LJU and DBV to CDG are on Hop! Air, which is an Air France partner. Also, due to limited flight selections out of Dubrovnik, we have an overnight at CDG (booked an airport hotel). Hope this helps.