Fertility could come back even after a long time of HRT. It could also be gone forever after a suprisingly short while. But yes. Normally, 6 months is what is said to be the line after which you shouldn't expect fertility to come back.
It's very variable, and I don't think you can ever know for sure. Personally, I've given up on having biological children long ago. I couldn't stand the thought of technically fathering a child. Besides, my genes aren't exactly something I want to transmit. Finally, even if I really wanted biological children, would it be worth the pain in the butt and costs that sperm banking and in-vitro fecondation imply? For me, no.
Your answer might be very different, but if I were you, I'd just raise my shoulders and tell myself that adopted children are my children just as much as biological children. Besides, if you're going to be with a woman, you could very well do like so many lesbian couples who resort to strangers' sperm and just not be the bearing mother. Wouldn't make you less of a mother.