Podgorica remains one of Europe's quieter capitals, which is precisely what makes the routing puzzle from New England so interesting. There is no nonstop option, so business class from Providence to Podgorica requires a transfer, and the most reliable itinerary I've found over years of booking this corridor runs through Delta's partnership network via JFK or Boston to a European gateway, then onward via Star Alliance metal from either Frankfurt or Istanbul. Lufthansa's connection through Frankfurt is the workhorse here — expect their long-haul aircraft on the transatlantic leg (increasingly featuring the new Allegris business suite on select routes, though legacy business seats still populate much of the fleet) before a short regional hop down to Montenegro. Turkish Airlines via Istanbul is the other serious contender, and in my experience it's often the more comfortable overall journey, thanks to Turkish's generous business class catering and the ease of connecting through IST's modern hub layout.
The insider move that most travelers miss: book the transatlantic segment on Delta metal out of JFK using Delta One (their reverse-herringbone suites with doors are now standard on most European-bound widebodies), then let a codeshare or separate Star Alliance ticket handle the Istanbul or Frankfurt-to-Podgorica leg — mixing airline alliances this way often unlocks better award availability than trying to force a single-alliance itinerary. Arriving into Podgorica's compact airport is refreshingly simple; there's no need to buffer extra time for immigration or baggage as you would at larger EU hubs, though I'd still build in at least a 90-minute connection in Frankfurt or Istanbul given occasional gate changes.
Seasonality matters enormously on this route. January through March and October into November consistently produce the most attractive business class fares, largely because Montenegro's coastal tourism season collapses after summer, softening demand on both legs of the journey. Given how thin premium cabin allocations are on the regional connector flights into Podgorica, I'd strongly recommend setting up automated fare tracking rather than checking manually — award space and mileage-run rates on this itinerary can shift week to week without warning.