It may well be due to the HRT. One of the symptoms of the menopause is general fatigue.so the HRT corrects that by tuning up your body, turning the clock back to your younger days. More energy needs feeding, so you you may find a slight reduction in your basal insulin will fix that. You will find your hair will improve its texture.
You may well not find any info about HRT and Type 1, because Type 1 is relatively rare, and so is HRT, but that is getting more widely used now, since most of the early studies that suggested an increase in breast cancer have been discredited.