Cannot restore iPhone from previous iPhone

I got an iPhone 7 Plus in August 2017, so I sold my iPhone 6 to my friend and erased its content. I transferred all my photos onto my new phone, but I really want to restore my phone from a backup in June 2017 because some reason I deleted some vacation pictures before I got my new phone. I’ve tried every way to restore from a backup from the summer but the earliest backup is August 2017 (when I got my new phone). I probably just have to take it to Geek Squad or Apple to see how far they can dig into my backups.