I get where you are coming from.
I would look beyond just the vacation, and look forward, to a lifestyle!
Life throws us crap all the time. Vacations, weddings, graduations, holidays, babies, yada, yada.
We can do everything right day in and day out, and not make, "the goal"
That is in all reality ok.
What I learned is this! It has to be a realistic, lifestyle, not just "ONE" "THING"
Do the best you can with your current goal, but, look beyond that, long term.
Life can be crap shoot! I thought I had it by the tail, last spring. Well, that went in the crapper.
It's long story, but, there were days, when I had to choose, food, or workout, I did not have, due to family stuff, stress, the will to do both.
So, each morning, I had to, when I got up, choose. Some days it was food, some days it was, exercise.
It was hard. But, I made it! One choice at a time.