Mine's 8 ft wide, with the door in the middle of the 8ft , so the sheds 6 ft deep. My bikes sit in there ok, with just a slight angling of the h/bars. 3 bikes on one side, 2 on the other. You do have to move the bikes a bit if you want one of the ones furthest away from the door, but it's no problem.
If you can find a good shed outlet (not B&Q fer chrissakes
), they will usually tailor it to your specs.