I'd like to share my perspective on your dilemma, if that's OK.
Eight years ago, I had to have a hysterectomy because of a severe prolapse. At that time, I elected to have my ovaries removed and go on HRT. In hindsight, I'm not sure I'd make that same choice again now that I know how hard it can be to balance one's hormones using HRTs and also how much they can cost!
Be that as it may, two years later, and again four years later, I was diagnosed with estrogen receptor positive (ER+) and progesterone receptor positive (PR+) breast cancer. My DRs told me at that time that my HRTs were not a factor in causing the cancer, since by the time it was big enough to see in a mammogram I'd already had it for seven to ten years.
The first oncologist I went to see wanted me to stop my HRTs and go on Tamoxifen. In trying to decide whether or not I was willing to try those things, I asked her, "if I had kept my ovaries, would you be telling me to have them removed?" and she replied, "of course not".
I won't bore you with the rest of the story... you already heard the important part.
But I will say, remember, estrogen does not cause breast cancer the way it causes endometrial hyperplasia. There IS a metabolite of estrone, a weak form of estrogen that is the one that menopausal women make in abdominal fat cells even if they no longer have ovaries, which can cause breast tumors in rats; but there are ways to influence the way you metabolize estrone so that that isn't an issue. Also, women with working ovaries or who are on adequate HRT tend to make less estrone.
One other thing... was whomever in your family had breast cancer tested for BRCA1/2, and have you been tested? Family history is just one of many risk factors for breast cancer, and actually, most women who are diagnosed with breast cancer had no family history (myself included).
I'd also question the advisability of keeping the cervix in situations where there is endometrial hyperplasia. There is no 'dotted line' between the cervix, which is just the neck of the uterus, and the rest of the uterus that tells the DR where to cut. I would think that if the uterus was at risk for cancer, then there could easily be cells left behind if the cervix is kept which might be able to develop that same cancer.
I'm glad you're thinking this through ahead of time... it sounds like you have time to really weigh your options and make the best decision for you. Best of luck with whatever you decide to do.