As you said we need time, at least for me time is the biggest enemy.
I have to divide my time between working 8 hours a day and travelling on weekends and holidays.
I can still travel when I take a week off, which can be summer or even winter, yes, I have an understanding boss.
To come back to the Fagaras Fortress, it really is a must visit, it is amazing, more than that if we are interested in history we can learn interesting things.
Have a wonderful weekend.