Good news guys, I did another measurement but this time I use the ground to take it from, last night I was doing it from the top. Here are the pics of how I did the final measurements:
Aline to the tip of tongue and use bin to hold it down
That is about 224 inches which is less than your garage length and less than the specs in the brochure
224" = 18' 8"
But double check to what your getting, it may change since mine is a 2012 A128S
Happy shopping for an A-Frame! I did that last year and it was more enjoyable than when I got my SUV