Hagrids is pretty much long all day, even during the slow seasons. Not many times is it under an hour. Of course, it's worse during holiday weeks.
There's no good solution. The attraction is excellent, and super popular. The only way to cut stand by to 'reasonable' times is if they can upwardly adjust the operational capacity, which may not be possible. I don't think it's running at the capacity they envisioned when they developed the ride, but that scenario may have been overly optimistic. Even a new park, Epic, with all new attractions, has not dented the demand for Hagrids. That's a testament of how great the attraction is
And, a lot of tourists and AP holders can only go when their schedule, or their kids schedule, allow. So, with no express they have little opportunity to ride Hagrids unless they can squeeze in a couple hours of their vacation time for one ride.