Lots of dryhops can clog up your siphon, but careful racking is all that's needed.
I suggest starting the siphon in the middle of the beer, and then lowering the racking cane down as the level of the beer drops.
If you're not all that proficient with racking, hops bags (sanitized first, of course) work just fine.
Here's a photo of a couple of my carboys (towel is off just for the photo!):