Apple in store trade in program

Hi, I plan on standing in line tomorrow night to try and get an iphone 6+ in white/silver 64gb. I wanted to trade my current iphone 5s gold 16gb at the same time of purchasing the new 6+. Is that possible? Or should I do it the night before the store closes? Also, what would I get for my 5s (it's mint, like new no scratches or anything at all) Thanks!