Providence's compact Green Airport doesn't send anyone directly to Hannover, but that's precisely what makes routing strategy the whole game here. There is no nonstop business class from Providence to Hannover; the smartest itineraries funnel through Delta's Atlantic gateways via JFK or Boston into Amsterdam or Paris, through American's partnership network via Philadelphia into Frankfurt or Munich, or through United's Newark hub direct into Frankfurt, with a short onward hop or train connection into Hannover itself. I've flown this corridor enough times to know that the Frankfurt-to-Hannover rail link (roughly ninety minutes, often bookable on the same ticket) is frequently a smarter, less stressful choice than a tight regional connection through a smaller German airport, especially after a long transatlantic haul.
On the transatlantic long-haul segment, Delta's A330-900 or A350 business class, with its suite-style seating and direct aisle access, remains the standout hard product on this routing, while United's Polaris seats on 767s and 777s out of Newark offer solid lie-flat comfort and a dedicated Polaris lounge if your connection allows a layover there. American's business class, often on 777s or 787s routed through Philadelphia, tends to pair well with oneworld partner Lufthansa or British Airways metal for the European leg, and I've found that booking the American-operated transatlantic segment paired with a partner short-hop into Frankfurt often yields the smoothest overall experience. My insider tip: build in at least a two-hour buffer at your European hub before the Hannover connector, since German domestic gates can be a healthy walk from international arrivals, and delays cascade quickly during winter weather months.
Seasonally, January through March and again in October and November tend to offer the loosest award space and softest fares on this route, as Hannover's trade-show calendar (notably CeBIT-era events and Hannover Messe in April) pushes business travel demand and pricing upward outside those windows. Given how much these fares fluctuate hub-to-hub, setting up automated fare tracking for this specific Providence-to-Hannover corridor is the easiest way to catch the inevitable dips before they disappear.