The good thing about the Mirena coil - if you tolerate it well - is that you can use any oestrogen patch or gel whether you are peri or post menopause. It would just be the dose that's different. Many women start off on a low dose oestrogen if very early in peri and experiencing symptoms, and then increase it as their own oestrogen declines, and then again after a few years if they want to stay on it, perhpas reduce to a medium or low dose if this controls symptoms.
I've said before that I've always used Estradot patches since using oestrogen and progesterone HRT, and these are very small and come in doses from 25 mcg right up to 100 mcg. others swear by gel! It's a personal choice - if you want to change a patch twice weekly, or apply gel daily.
Let us know how you get on!
Hurdity x