East or west Kentucky? If west I’d say Madone, east then Emonda, if the roads are very low quality and/or you might venture onto gravel then Domane. Perhaps also Domane if you just want a more comfortable position on the bike.
I have a 2020 Madone and it’s a bit more compliant than the 2017 Supersix HM she replaced. I had a 2013 Domane and enjoyed it a lot although the fitter I use these days couldn’t get the bars low enough so I sold it. The Isospeed has taken on a whole different shape since 2013 so I don’t think there’s any comparison for me to share worth taking into consideration. I live in the middle of a load of rolling hills, some of which do run a little steep but short. In my decision making the hills aren’t long enough to say the Emonda would make a big difference, if any, versus a Madone so I went the more aerodynamic direction. I didn’t consider the Domane at all as it wasn’t the type of bike position I was looking to get into again.