Reine,
As much as some folks want to be exclusionary, I am absolutely certain that you are correct - that there is a scale of "discomfort" or "intensity" for those of us whose internal gender identity does not match their birth gender. Fetishists aside, I believe that this discomfort is alleviated by some degree of presenting in your internal gender, going all the way to needing to permanently transition to your internal gender. MTF 10-90%, 50-50%, 80-20%, whatever works, up to 100% full transition. Again, it is whatever works to alleviate the individuals gender "discomfort."
Now to answer you question: Complicated for me. I have done a lot of soul searching, looking back at my life (as accurately as one can do that), and think that given how I think I felt as a kid and a teenager, IF I had supportive parents and IF society was more like now and less like it was then, I would probably be a woman now. But. . .
I am in my mid 40's with a male body that has suffered the ravages of a male life all these years. I am madly in love with my wife, and yes, your question is "if she were onboard," but I am extremely satisfied, to be the man in her life and the father to my children. Finally, and I will admit that maybe it is a lifetime of being "conditioned" as a man, there are aspects of my life that I want to experience as a man and not as a woman. Maybe conditioning, maybe 40+ years of male privilege, whatever the case I AM happy and comfortable being a man at times. I still haven't figured out what percentage in what gender I need to be perfectly happy - I'm starting to think that it is a constantly moving target, but a life in two genders seems to be working.
Going back to a matter of degree, sometimes miserable and sometimes fine.
Bringing things back to the OP:
Thats it!!!! I read something that really resonated with me - Julia Serrano I think.
She was asked after she transitioned if she sometimes went into the wrong restroom by mistake. Her reply was that she never in her life went up to those restroom doors without consciously considering her gender and which was the "correct" door for her to enter. That hit real close to home!
I think this is true. I think that if more people in this world were true to themselves, whatever that may be, it would be a better world.