I'm 7" by 6" thick, I've had no issue going balls deep in every single woman I've been with. These women have ranged from petite 5 foot nothing tall, to taller than average, and from fit and skinny, to curves in all the right places.
Only a small handful of times, usually while fucking doggy style, have I gone deep enough to 'poke' something that made the woman uncomfortable. A slight change in position, and we were pounding away again. My girth has meant that I have used lube with most women, just for ease of entry. Once inside, they all have been able to easily accommodate 100% of me and have really enjoyed being "filled up".