Best airport to get to Bayonne

I will be following this as we are also taking this tour next May and will also coming from Seville. So far, it looks like the AVE train from Seville to Madrid, flight to San Sebastián (the airport is actually in Irun/Hendaye area) and then a short train ride to Bayonne. However, I’m open to other suggestions.

I would just fly from Seville to San Sebastián with a change in Madrid, rather than taking the train to Madrid first.
The airport in San Sebastián is a quick taxi ride away from Hendaye train station, where you can take trains to Bayonne. There might be buses, too, but I am not sure.

If you can find a good flight from Seville to Bordeaux, it would be OK as well, but the direct flights I see (Ryanair on some days) require an overnight in Bordeaux.

And don't discount flying to Biarritz via Paris Orly. On Transavia, it would not be that expensive, and Orly is compact for connections. Once at Biarritz airport, you can take a city bus to Bayonne.

I agree with balso. If you're going to fly from Madrid up to San Sebastian anyway, why not start flying from Seville.

Both Vueling and Volotea have direct flights from Seville to Bilbao, which would mean less air time and quite likely less travel time overall. Bilbao is a larger airport than San Sebastian, and I believe it has bus service to SS. I've only traveled on the ground in the Spanish Basque Country and haven't crossed the border in that area, so I don't know what would be the best way to get from the Bilbao airport to the Hendaye train station--whether there's an option besides bus to SS and then taxi to Hendaye.

If you opt to connect in Madrid, be aware of whether your itinerary involves a real, protected connection or whether it's two separate tickets. The latter would leave you on your own if you were unable to make the connection in Madrid--such as if the intial flight was canceled.