They make the awnings a little shorter than the minimum. We just ordered one for our 14 ft awning, and it is 154" or 12'10". A 12-13ft room is 130", or 10'10".
Now you might think 'we could squeak a 14-15 ft awning under our 13 ft, as it is only 12'10", but don't forget that the actual width of your awning is about 6" less than your advertised width.
Rv Supply Warehouse has the 12-13' on sale for $512 with free shipping, and PPL has them on for even less, $440 plus a reasonable shipping charge, but only until the end of June.
I checked out a friend's brand new Vacationer room, and while it is a lot lighter fabric than the old addaroom we had before, I do like the way it mounts to the camper without having to drill holes in the walls of my brand new Flagstaff! For the price, it was good enough for me.