On a slightly related note of wide angles and iPhones... I highly recommend the Olloclip 4-in-1 lens thingy I've got for my iPhone 6. Slots over the top and gives a fisheye or wide angle FOV, and if you unscrew them it gives you a 15x or 10x macro. Great fun. IQ is surprisingly good too, which is a bonus. Only downside is that it doesn't fit a phone with a case, so you have to use the phone 'naked'.
I absolutely love my 7D, and would take it everywhere if I could, but for quick snapshots I can't argue with the iPhone. I'm assuming if you took your D750 you'd have a long lens to take as well? Having something like a 70-200 in the bag trumps almost all compact cameras and especially phones.