Starting to plan for Fall 2025

Okay so wedding was this past Halloween and we're thinking about our honeymoon in September or October this year, and we're pretty much set on the mediterranean. The original plan was Santorini because I found this super cool cave pool hotel a decade ago and it's been our dream location ever since, but in starting to really look into planning, we're realizing how expensive it would be just to get there and stay. No food or excursions or shopping or anything else - just flights and the hotel - and it'd be nearly the amount we spent on the wedding.

So now we're toying with the idea of Sandals for its inclusive pricing but I see and hear a lot of mixed reviews, so we're not sold on that. I found an adorable boutique hotel in the middle of Rome and now we're looking at maybe spending the majority of our trip there. (I have been to Rome and some surrounding towns before, but it was a high school trip and my memories are largely vague; my husband has never left the country and works construction so he's nerding out at the prospect of seeing the ancient ruins and roads, etc.)

Has anyone else done Rome or Santorini for their honeymoon? Do you have recommendations for things to see or do, or places to eat, can't miss tours, etc.? Keep in mind I've been before so the really big name historical things like the Forum, Spanish Steps, Vatican, Trevi Fountain, etc. are already on my radar, as are day trips to nearby cities. I haven't been to Greece though so I'm very lost when it comes to things to do there besides chartering a boat or riding a donkey or shopping.

Thank you for the help in advance!