Let's imagine following scenario:

Human society, mostly possessing technology on level of continental Europe, around year 1000 AD ("High Medieval Period"). 

There are rare, but not unknown, artifacts of much higher sophistication, including firearms, watches and even mechanical calculators. People can repair them, even make new ones, but only with great expense and effort, since each part has to be handmade individually, and by a skilled specialist. 

The society has also access to, considerable, population of Asian Elephants. They also have considerable knowledge of animal husbandry, and understand Mendelian genetics. 

Would it be possible, within say three to four centuries, to breed these elephants into more obedient creatures? And to acquire tolerance of lower temperatures, comparable to European temperate climate?