Lock In What You Want & Decide Later
Apple won't charge your credit card until your iPhone 7 is preparing to ship so it might be a good idea to lock in an order now and decide what to do later.
Put in an order for the iPhone 7 or iPhone 7 Plus model you want and then take a wait and see approach as we move toward the release date and the month of October.
If you're lucky, shipping dates might improve at your carrier or at a retailer. If this happens, you can cancel your order without penalty.
If you're unable to find a better option, well, then you'll have a package from Apple to look forward to.