Rhinos can still work, but you need to either use 2-3 of them + other armored targets to draw fire, or need some kind of sneaky way of keeping them alive on that first/second turn. The old Space Wolf spam list (nothing but Grey Hunters and Long Fangs) doesn't have the teeth it once did, simply because the Rhinos are much easier targets. You'll need to adapt your list design to draw AT fire away from the Rhinos or find a way to make them tougher.
As for Grey Hunters, they're about as good as they ever were, pretty much. Missile Launchers aren't *quite* as good as they were, but they're almost the same (you won't be one-shotting vehicles as often, but rather stripping hull points). You don't have any Anti-Aircraft fire, so investment in a fortification with a Flakk gun isn't a bad idea if they're just going to be sitting still, anyway.
I don't think the Space Wolves are hopeless by any means, but your old bag of 5th Edition tricks won't work quite the same way anymore.