The Sanga has played 14 series outside the subcontinent. If we take an average of 40+ as being good for a series, the Sanga has had 4 such series in 14! Out of these 4, one of was the recently concluded test series in England on dead tracks(I think Vijay in the first two tests - one of which was a track livelier than any the Sanga has faced - scored more than pretty much every series Sanga has played outside of Galle, Colombo, Kandy, Lahore, Faisalabad..and of course Dhaka). All of these 4 series are 2 test series or less(the Australian 'series') - so much for lack of opportunities when he hasn't been able to average 40+ in a single 3 test series outside the subcontinent ever. If anything the shorter series have helped him.
While our half Hyderabadi and half Banglorean friends might not like it and resort to ad hominem to try and make the Sanga look better, it is what it is. Just for fun, if the same criteria was applied to some other batsmen..this is what it would be :
Rahane has 2 such series out of 2 (likely to make it 3/3 in England)!
Kohli has 2 such series out of 4 (likely to become 2/5 as his current series has been poor)...
Clearly Kohli has missed a trick. After this series he should refuse to play any cricket away from the subcontinent. Just play Pakistan a lot in the UAE and about 15 straight tests against Bangladesh...maybe 5 tests against SL for good measure. He'll go down as an ATG then.
Out of current batsmen, Ab de Villiers averages 40 against and in every country (bar Bangladesh). Easily the best batsman going around, averages that without having to cherry pick matches at random and averages 50+ even when he kept presumably. Greatest batsman of the post Tendulkar/Lara/Ponting generation. Amla and Clarke are next.