I don't know about snorted, but from my experience two 8mg (16mg) hydromorphone IV is a bit stronger than 100mg of IV morphine.
Orally i believe is around 4-5x morphine. But you can't really snort morphine. Snorted hydromorphone to oral morphine is probably more like 6x.
If you're up for it (or rather, down for it) my guess is that plugging around half of a 100mg morphine tablet would be about equal to 9mg of snorted hydromorphone.