I'm about an inch shorter and love doggy style and I have had partners who had issues with that position as well. A couple of women just didn't want me screwing them that way, and a couple of others would let me, but I had to be continuously aware of how deep I was going and restrain myself which took some of the fun out of it.
With most partners I have had doggy style sex with, my knees wound up positioned between hers which were spread so that I could kneel between her calves. I found sometimes that having her knees together and maybe her ankles crossed, and my knees outside of hers resulted in slightly less deep penetration. It also tended to raise the woman's vulva relative to the root of my cock so that I was directed more upward towards her spine, which seemed to help avoid cervical contact sometimes.