PM, all of our QCs are switchable between B1 and B2 (20k or 22k) and are always B2 for passenger ops. They have better performance than a standard airframe with B1s.
How long is the runway?
Field length limit for a B1 at 22C, flap 5, sea level with no corrections is 64.2 tonnes for a 9000' runway which is above MTOM.
I can't recall the distance to obstacles at Malaga but for comparison a 500' obstacle at 5NM gives a limited weight of 53.6 tonnes.
An empty B1 is about 33.5 tonnes APS. Stick on 14 tonnes of people and bags and roughly 9 tonnes of gas and you're getting close.