I wouldn't recommend rope dropping it unless you're past the bridge and maybe past the Will Call booths at Islands of Adventure (in terms of waiting to enter the park). If you're not yet on the bridge, don't bother. EVERYONE will be running to Hagrids. Also I'm not sure if I'm very unlucky, but every time I've done early entry Hagrid's was down the entire time and when it came back up, it was a 200 minute wait. I would use early entry for doing wand magic/Ollivanders, having breakfast at Three Broomsticks as when the park opens to day guests, that place had a very long line to get in or ride Forbidden Journey and/or Velocicoaster.
I recommend riding around typical dinner time (around 4-6 pm) or wait to hop in 30-ish minutes before the park closes. When I went in May, Hagrid's was a solid 3 hour wait the entire day but dropped to 65 around 4. Truthfully you will be waiting at least 60 minutes no matter when you hop on line, so I would grab a drink from Three Broomsticks (hot butterbeer RULES!) and hop on line then. When it's busy, Universal will close the line for capacity early before park close, so that's why I say to hop on line 30 or so minutes before the park closes.
The ride really is worth the hassle. Hagrid's is awesome! Totally worth a 65 minute wait. The line is always moving since there is no Express, so it wasn't as bad as waiting in line at Disney.