When biking to Leh it is advisable to travel at a slow pace to allow acclimatization. A suggested itinerary is: Day 1 Manali - Jispa (138 km; 86 mi), Day 2 Jispa - Pang (161 km; 100 mi), and Day 3 Pang -Leh (174 km; 108 mi).
Screen repairs cost $109 for an iPhone 6 and $129 for the iPhone 6 Plus. If the Apple store near you has the parts, it will repair your phone. If it doesn't, it may replace it. There is a slim chance it may be sent out for repair. AT&T will not be involved in the repair nor will it be notified.
On rare occasions when there are no longer refurbished units for your older model, they may replace it with the next newer model. ATTN: Beginning July 2013 Apple Stores are now equipped to do screen repairs/replacements in-house on iPhone 5 and 5C. In some cases while you wait. According to Apple this is the beginning of equipping Apple Stores with the resources needed to do most repairs for iPhones, iPads, and iPod Touches that would not require major replacements.