One of the things I think we all fear when beginning to present our authentic selves in public is rejection by many of those around us. It came as a surprise to me, and to most of the other trans women I know, when this in fact did not happen. Most, particularly women, were very accepting and encouraging. In the early days, I would often refer to myself as being under construction. This was acknowledged without comment or criticism. The surprising thing was how readily they accepted me as part of the sorority and treated me just like any other girl. It was tremendously affirming. I suspect when you have the opportunity to take another vacation, you will find your experience to be very much the same and equally rewarding. I certainly hope this happens.
I think there are two things at work here. As you suggested, being confident and presenting a friendly demeanor goes a long way in determining how you are received. More fundamentally, however, I think women in particular recognize others with the same paradigm and values. They accept us as women because that is who we are innately at our core. We just naturally fit in. Our roles as males were a learned behavior and always a bit forced. It is not who we really are.
I am the same age as you and am now post op and completely passable. I am a little shorter (6’) and a touch heavier, but other than being tall, I am rather unremarkable. I am never misgendered anymore. It has allowed me to fully live my life as my authentic self. It grieves me that your wife does not accept the real you and requires you to keep your female identity hidden in her presence. But it is encouraging that at least she has been able to remain married. That is a positive sign, no matter how tenuous things may seem currently. I deeply hope that with time will come greater understanding. It is a shock to an innocent spouse when she realizes that the man she thought she married is really someone quite different. It takes time to adjust. Even with the change of identity, deep down you are the same caring and loving person you have always been. My most fervent hope is that is what will preserve your relationship and ultimately allow you to develop a new and even deeper one. Transitioning is hard. Transitioning at a mature age is harder still.