I mean footprint size yes. Anything bigger than the current 4.7" and I really won't buy it. If the screen increases within that then that's only positive. I was offered a 6S Plus last year as a work phone and declined it. I just hate large phones and won't even entertain buying them.
I'll see how much the iPhone 8 is next September but if the price is still high, I'd rather get a 7S with a screen I prefer anyway.
Just my opinion but I thought the same regarding the larger screen iPads and iPhones till I tried them out. I thought the 7 lus was a huge giant of a phone but once I got used to it, I would never go down to a smaller screen. I used to buy 9.7 iPads but after I tried out the 12.9, I have gotten used to it over the past couple of weeks and I am actually finding it tiring to read on the smaller 9.7. You should try out the larger devices at least