Hi Bluebell, I'm so sorry to hear about the palpitations. I know just how unnerving they are - I had them in long episodes day & night for several years in peri & they continued postmenopause. The worst were usually during the night. I'm mid-late 50's so not quite in the age bracket you want to hear from, but have the T shirt in every colour with this horrible symptom & have had all the related checks like you, which showed mine were harmless ectopics. They continued until around 3 years postmenopause, which was when I began HRT, but also had my thyroid meds changed around the same time, so either could have been a factor in getting rid of the palps. I do find I can no longer tolerate alcohol, not specifically in relation to palps but because for me it makes flushing & sweats worse, though my palps were often part & parcel of the overheating episodes. Though you only drink a little, might be worth stopping altogether for a while to see whether that gets rid of the palps? You could also see your GP again to put your mind at rest.
It's a subject that's been discussed often on the forum, so maybe put palpitations/irregular heart beat or similar into the search box to hear others' experiences if this might help. I hope you manage to get to the bottom of it & see them off for good. They are truly horrible & were the worst menopause symptom for me.
Wx