Madeira's volcanic runway has humbled many pilots, but reaching it in comfort is entirely achievable if you know how to route around the Atlantic's connection puzzle. There is no nonstop option for business class from Seattle to Funchal, so the real decision is which European gateway suits your travel style: London, Frankfurt, or Lisbon. British Airways routes through Heathrow Terminal 5, where the Club Suite's sliding door and direct-aisle access on the 787 make the transatlantic leg genuinely restful, though you'll then transfer to a narrowbody or regional aircraft for the Funchal hop, as BA doesn't fly that final segment itself—TAP does. That's precisely why I steer most clients toward TAP Air Portugal via Lisbon, since TAP is Portugal's flag carrier and the only airline with true metal all the way into Madeira, meaning fewer handoffs and less luggage anxiety. Lufthansa, connecting through Frankfurt, is worth considering if you're coming from a Star Alliance loyalty base, and their newer long-haul cabins on select 787 and A350 routes offer excellent privacy, though again you'll transfer onto a partner or TAP-operated segment for the island landing.
My strongest insider tip: book the Lisbon layover deliberately long—four to six hours—rather than treating it as dead time. TAP's Lisbon hub allows you to clear immigration, decompress in a lounge, and catch the tighter, often turbulence-prone descent into Funchal well-rested rather than jet-lagged and rattled. The island's runway, built on stilts over the ocean, rewards a calm nervous system.
Seasonally, January through March and again in October and November are when premium cabins to Madeira soften considerably, as the island's spring and autumn shoulder seasons see less European leisure demand than the summer crush. Given how thin business class award and paid inventory can get on the Lisbon-Funchal leg specifically, I'd recommend setting up fare alerts now rather than searching reactively—this route rewards patience and quick action in equal measure.