I think next album will be their last studio album. We all know what Nicko said about drumming after 70. And be honest, Bruce can not sing forever. I think we will see 2 more tours + farewell tour. LOTB, new album tour and farewell tour.
In Maiden case farewell tour will be FAREWELL, not like KISS and bands like that. Maiden farewell tour could be 3 years long. I hope they will play at least 1 concert in every country they played in their concert history. That would be very honest.
Their last concert, maybe 2, should be played at London Olympic stadium (West Ham United plays there, concert capacity 80.000) which is just 1, 5 miles walking distance from Cart & Horses where they started. They could play 90 minutes, than 20 minutes break, than another 60 or 90 minutes. That way they could play bunch of songs on their last concert. That would be great event. Fans from all over the world would come to that gig.